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General Solution for Polynomial Equations?

An anonymous reader writes "On september 9, several media reported that a young Dutch student found a formula to determine the roots of any polynomial equation. Does this conflict with Abel's proof that such a formula cannot exist? Here is the news item (in Dutch) on his school's homepage." Another reader writes "A Dutch student at the Fontys school of physics has solved a math problem of several centuries old: finding the roots of any polynomial equation. Arxciv copy here. Although an exact solution has been proven impossible for higher orders, this is not the case for numeric solutions."

482 comments

  1. The fish by leonmergen · · Score: 5, Informative
    --
    - Leon Mergen
    http://www.solatis.com
    1. Re:The fish by Ctrl-Z · · Score: 4, Funny

      Is there a math-to-English translator for those of the Slashdot community that can't understand the PDF? Theoretically, I should be able to read it -- I have a degree in mathematics -- but we aren't all so lucky.

      --
      www.timcoleman.com is a total waste of your time. Never go there.
    2. Re:The fish by Anonymous Coward · · Score: 4, Funny

      Why did I keep expecting the words "bork bork bork" to come while reaing that?

    3. Re:The fish by 31415926535897 · · Score: 4, Funny

      I should be able to read it -- I have a degree in mathematics

      I'm guessing your degree was for English Mathematics. This paper is clearly in Dutch Mathematics (so, just head over to Babelfish).

    4. Re:The fish by Dashing+Leech · · Score: 5, Funny
      This paper is clearly in Dutch Mathematics

      At least it isn't in Polish Mathematics. Not only would it be difficult to decipher, you'd also have to read it backwards.

    5. Re:The fish by Josh+Booth · · Score: 4, Funny

      Does that mean you can read Reverse Polish math forewards?

    6. Re:The fish by quantaman · · Score: 2, Funny
      Is there a math-to-English translator for those of the Slashdot community that can't understand the PDF? Theoretically, I should be able to read it -- I have a degree in mathematics

      Hey, thanks for volunteering!!

      :)

      --
      I stole this Sig
    7. Re:The fish by Anonymous Coward · · Score: 0

      Reverse Polish Notation is not backwards. It's inside out.

    8. Re:The fish by jlcooke · · Score: 2, Informative

      bork bork bork? That's sweedish.

      That's fun is the Muppetizer that was on the www.muppets.com website before the evil Disney took it over. I have a copy of it here.

      Even funnier are the swear words they replaced!!!

    9. Re:The fish by Enigma_Man · · Score: 1

      There's only one "e" in Swedish, bork you very much.

      -Jesse

      --
      Nothing says "unprofessional job" like wrinkles in your duct tape.
    10. Re:The fish by TheWingThing · · Score: 1, Informative

      Ha ha, are you from USA? Sweden and Netherlands are not the same country.

    11. Re:The fish by apankrat · · Score: 4, Funny

      Sure, if your stack is big enough.

      --
      3.243F6A8885A308D313
    12. Re:The fish by Anonymous Coward · · Score: 0

      (wave Jedi hand) You don't want math in English. Haven't you have enough fun trying to figure you last income tax return. Tax rules are math operation in long tedious languages.

    13. Re:The fish by Anonymous Coward · · Score: 0

      It would also be incorrect.

    14. Re:The fish by thelenm · · Score: 2, Funny

      I have no stack. What? Where was I...

      --
      Use Ctrl-C instead of ESC in Vim!
    15. Re:The fish by Anonymous Coward · · Score: 0

      Funniest thing I've read today. God, I'm such a geek.

    16. Re:The fish by ahdeoz · · Score: 1

      there's 4 eyas is Sveedeech, ja?

  2. Re:Damn, 11 Years too late by Anonymous Coward · · Score: 0

    no you couldn't.

  3. Let me be the first by Anonymous Coward · · Score: 0, Funny

    Let me be the first to say that I welcome our new polynomial equation solving overlord. Let death come quickly to his enemies.

  4. All encryptions broken! by Anonymous Coward · · Score: 1, Funny

    So any polynomial time problems can now be solved in logarithmic time or something! Run for the hills! /sarcasm

    1. Re:All encryptions broken! by Anonymous Coward · · Score: 0

      i don't recall it saying that anywhere

      it just says that there is a solution to find the numeric roots of an arbitrary order polynomial.

      that solution may not necesarily be in logarithmic time.

    2. Re:All encryptions broken! by ChiRaven · · Score: 1

      So you're saying that ANY problem can now be mapped to an NP-Complete problem, for the purposes of solution? I assume that mapping is non-reversible.

    3. Re:All encryptions broken! by Zenzilla · · Score: 1

      uHM...Last time I checked matrix multiplication was THETA(n*m) or THETA(n^2) in an n*n matrix. No logrithmic solution here....

    4. Re:All encryptions broken! by A1kmm · · Score: 1

      Ignoring the fact that calculating the time an algorithm takes to run is not the same as running the algorithm, a note about matrix multiplication times...

      The most obvious iterative algorithm(i.e. direct from the definition) to multiply two nxn matrices would take theta(n^3). Strassen's divide-and-conquer algorithm, which divides the matrices into 4 submatrices, and does 3 recursive matrix multiplications, takes theta(n^log2(7)) = theta(n^2.81...)

      The best known algorithm in terms of asymptotic time is theta(n^2.376), but it does not surpass Strassen's algorithm until n is very huge, so Strassen's is the most practical algorithm known.

      --
      X-Has-Sig: yes
  5. Right in the middle of my Calc class too... by JoshieCK · · Score: 5, Funny

    Last quarter's PreCalc class said this was impossible? Now it's possible?
    Dang it, that means I'll have to buy a new math book for this quarter's Calc class, won't I?

    Ah, the world, she is a changin'...

    1. Re:Right in the middle of my Calc class too... by BlueCup · · Score: 2, Funny

      Man... I was thinking this was really cool. But now I'll probably have to buy a new book as well =( I think this is just a ploy by "the man" to sell more calc books... bastard.

      --
      WANNAWIKI Wannawiki WannaWiki WANNAWIKI!
    2. Re:Right in the middle of my Calc class too... by Sipos · · Score: 1, Redundant

      I think this gives you a numerical solution not an algebraic one which is impossible but I may be wrong (IANAM)

    3. Re:Right in the middle of my Calc class too... by Xyrus · · Score: 5, Insightful

      It's a NUMERIC solution, not an ALGEBRAIC solution.

      Abel's proof showed that polynomials with a degree higher than 4 could not be solved algebraically (i.e through a finite number of additions, subtractions, multiplications, etc.). Abel's proof did no say it was impossible to solve the equations (indeed, numerical solutions to these equations are solved regularly).

      This is similar to how some integral equation solutions cannot be expressed in simple terms. However numerical answers are rather easy to obtain (even easier with a computer) :).

      The method presented is a simpler way to find the roots of polynomial equations numerically by treating it like a power series (x, x^1, x^2,...,x^n) and applying standard differential techniques.

      Pretty cool if you ask me. :)

      ~X~

      --
      ~X~
    4. Re:Right in the middle of my Calc class too... by Zebbers · · Score: 1

      You'll have to buy new books anyways...How else will they fleece you?

    5. Re:Right in the middle of my Calc class too... by pjt33 · · Score: 4, Interesting

      It's a shame the paper doesn't say why this is better than using Sturm sequences, which work perfectly well.

    6. Re:Right in the middle of my Calc class too... by Xyrus · · Score: 2, Informative

      I agree the paper is lacking somewhat in describing why this algorithm is better. I looked into Sturm sequences. It appears that part of the algorithm is relying on a similar principal. The difference seems to come in when trying to converge on the root, which the student is using differential methods.

      But as you pointed out, I'm not sure what the advantage is in doing so. I wouldn't really classify that document as a paper, more like an empirical proof. It is not by any stretch rigorous (for instance you don't use the word "should" to describe a result from a step in a proof.

      ~X~

      --
      ~X~
    7. Re:Right in the middle of my Calc class too... by stupid_is · · Score: 1
      I was a mathematician, then I got a job and got trapped by Excel.

      I know it's not aimed at this, but I wonder what would happen if you threw Weierstrass at this

      --
      -- Intelligence is soluble in alcohol
    8. Re:Right in the middle of my Calc class too... by slashrogue · · Score: 4, Funny

      I would agree with it being cool if I understood any of what you just said. :\

    9. Re:Right in the middle of my Calc class too... by Anonymous Coward · · Score: 0

      I often wonder about Slashdot submitters who write things like "Does this conflict with Abel's proof". No, Abel proved it, that's what "proof" means.

    10. Re:Right in the middle of my Calc class too... by MemoryAid · · Score: 2, Funny
      Last quarter's PreCalc class said this was impossible?

      Anything is possible at Zombo.com.

      --
      Language students: Don't try to learn English here. This ain't it.
    11. Re:Right in the middle of my Calc class too... by rmstar · · Score: 1

      Standard methods for doing this have existed for ages. The problem is well understood and many many methods are known for solving this problem.

      You cannot get numerical solutions to every polynomial. You can write polynomials whose roots vary wildly if you change one coefficient by only a very tiny amount, which means that inexact arithmetic (floating point) can only give you meaningless results in those cases.

    12. Re:Right in the middle of my Calc class too... by flibuste · · Score: 1

      It's a NUMERIC solution, not an ALGEBRAIC solution.

      That was time somebody clarified this for the math-challendged slashdotters.

      Reading the PDF demonstration, it's pretty clear that it is simply an algorithm for computing roots numerically, not calculating them.

      I'd mod you "At least somebody who makes sense" Thanks
    13. Re:Right in the middle of my Calc class too... by kimota · · Score: 1

      And just to add insult to injury, you won't be able to sell back the math book you have!

      --Kimota!

      --
      Who moderates the meta-moderators?
    14. Re:Right in the middle of my Calc class too... by hunterx11 · · Score: 1

      Newton proved the laws of motion, and did a pretty damn good job at it too. Surely there's no point looking any further than his laws :)

      --
      English is easier said than done.
    15. Re:Right in the middle of my Calc class too... by thing12 · · Score: 1

      The unattainable is unknown at Zombo.com

    16. Re:Right in the middle of my Calc class too... by Austerity+Empowers · · Score: 3, Informative

      In the event you weren't joking (I'm sure lots of people don't know what he means), I believe it means that there will never be a magic equation to 4th order polynomials and above like one learned in algebra to the 2nd order polynomial:
      ax^2+bx+c =0
      which is:
      x= (-b +- sqrt(b^2-4ac))/2a
      (aka the quadratic equation)

      Instead you can get VALUES for the roots by using algorithmic approaches, but you cannot come up with a generalized equation like the quadratic equation above.

      If it still doesn't make sense, then it probably doesn't matter, but some lines of engineering require finding roots of high order polynomials. I haven't done it since school, so my whole post may be wrong, but there's your explanation =)

    17. Re:Right in the middle of my Calc class too... by Anonymous Coward · · Score: 0

      Yep, that was worth $100. Of course, you could tell your prof that you could not find any of the used books that cost $90 or that you are waiting for the next edition.

    18. Re:Right in the middle of my Calc class too... by BizidyDizidy · · Score: 1

      Hahaha, good one. This is the funniest post I've read all day. I commend you, faux intelligent man.

      --
      The safest way to approach lava is to have another person with you and he goes first.
    19. Re:Right in the middle of my Calc class too... by aardvarkjoe · · Score: 4, Informative
      I believe it means that there will never be a magic equation to 4th order polynomials and above like one learned in algebra to the 2nd order polynomial.
      Fifth order, I believe; there actually is a quartic equation to solving a 4th-order polynomial algebraically. (Although admittedly, even with the equation I'd hate to try to do it by hand.)
      --

      How can we continue to believe in a just universe and freedom to eat crackers if we have no ale?
    20. Re:Right in the middle of my Calc class too... by logicnazi · · Score: 2, Interesting

      I already made a long post explaining the article (if you are really curious look at my recent posts) but I needed to point out here that you forgot radicals in your descriptiong. Even the quadratic isn't solveable in terms of finite additions subtractions, multiplications. Abel's theorem says that you can't solve the general polynomial of degree five or higher using addition, multiplication and taking nth-roots.

      Personally, I am entierly unimpressed with this paper. The numerical method involved looks horridly inefficent (newton's method is probably pragmatically more interesting) and the math itself seems pretty uninspired.

      --

      If you liked this thought maybe you would find my blog nice too:

    21. Re:Right in the middle of my Calc class too... by logicnazi · · Score: 2, Interesting

      Hmm...I don't have a source but I'm pretty sure you are incorrect. Sure *fixed width* floating point solutions won't work but this is hardly enough to show there is no general numeric solution.

      I'm pretty sure there is a general numerical solution doing something fairly simple (a little better than newton's method). Of course it is entierly inefficent and practically useless.

      --

      If you liked this thought maybe you would find my blog nice too:

    22. Re:Right in the middle of my Calc class too... by slashrogue · · Score: 1

      Quadratic equation... it's sort of coming back to me now. I knew there was a reason I slept in math class.

    23. Re:Right in the middle of my Calc class too... by orasio · · Score: 1

      But if you did the calculations with the help of a computer, it might be better to use a numerical method, where the error iduced by FP representation is already taken into account.

    24. Re:Right in the middle of my Calc class too... by Kwantus · · Score: 1

      I thought Abel showed it only for 5 and it was Galois that showed it for the rest?

    25. Re:Right in the middle of my Calc class too... by Trinition · · Score: 1

      Dang it, that means I'll have to buy a new math book for this quarter's Calc class, won't I?

      Umm, you haven't been in college long, have you? You might as well get used to having to buy a new book for a subject every quarter even if there aren't any ground-breaking new discoveries!

  6. /.ed after 4 comments by David+Horn · · Score: 1

    Well, I'd love to have seen the formula, but the site's gone down.

    --
    PocketGamer.org - For the gamer on the go!
    1. Re:/.ed after 4 comments by Anonymous Coward · · Score: 2, Informative
    2. Re:/.ed after 4 comments by cunniff · · Score: 5, Funny

      I have discovered a truly remarkable formula to solve any polynomial, but my site has too little bandwidth for me to post it here.

    3. Re:/.ed after 4 comments by Anonymous Coward · · Score: 0

      I think that has to be my favourite comment ever posted on /.

    4. Re:/.ed after 4 comments by CSG_SurferDude · · Score: 4, Funny

      Dang, I just started reading this, and you allready beat me to it! ;-)

      However, I am still typing up my GUT (I prove that there are only 17 dimensions, string theory is wrong, the Multiverse doesn't REALLY exist, and that the cat is alive or dead BEFORE you open the box), and should have it available for subscribers shortly.

    5. Re:/.ed after 4 comments by mikael · · Score: 3, Funny

      You can adjust the width of the margins using the HTML command.


      <BODY TOPMARGIN=(integer) LEFTMARGIN=(integer) MARGINHEIGHT=(integer) MARGINWIDTH=(integer)>

      That way, you'll never run out of space.

      --
      Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
    6. Re:/.ed after 4 comments by Gil-galad55 · · Score: 1

      If only I had mod points... and if only Fermat had HTML!

      --

      To follow knowledge like a sinking star, / Beyond the utmost bound of human thought. ("Ulysses", Tennyson)

    7. Re:/.ed after 4 comments by ray-auch · · Score: 1

      Per your .sig, life is even wierder than that - check out nomato ketchup, eg.

      here

      and yes it is serious - tomato ketchup for those who are allergic to tomatos...

    8. Re:/.ed after 4 comments by troon · · Score: 2, Informative

      Intended humour aside, that may work in many browsers, but it's not valid HTML.

      Use CSS styling instead.

      --
      Ydco co ,df C erb-y go. a Ekrpat t.fxrapev
    9. Re:/.ed after 4 comments by hunterx11 · · Score: 1

      And here I was, planning to build a Beowulf cluster of cats in boxes! Don't I feel foolish now, thinking I was going to break all sorts of encryption schemes by factoring large numbers based on the ratio of living cats to dead cats.

      --
      English is easier said than done.
    10. Re:/.ed after 4 comments by Anonymous Coward · · Score: 0

      Coming in a little late, but I've to say: Best. Comment. EVER! You rock.

    11. Re:/.ed after 4 comments by Anonymous Coward · · Score: 0

      I'll give Wiles a call and see if he has a few spare years.

    12. Re:/.ed after 4 comments by 808140 · · Score: 2, Funny

      If Fermat had had HTML, he woulda been able to fermat his own margins...

      Do I hear crickets?

    13. Re:/.ed after 4 comments by Anonymous Coward · · Score: 0

      Well, of course string theory is wrong, but as for the rest, you're way off base :)

    14. Re:/.ed after 4 comments by feloneous+cat · · Score: 1

      However, I am still typing up my GUT (I prove that there are only 17 dimensions, string theory is wrong, the Multiverse doesn't REALLY exist, and that the cat is alive or dead BEFORE you open the box), and should have it available for subscribers shortly.

      What you DIDN'T know is that I ate the cat in a nicely stewed cranberry sauce. Which is going to be a real bitch if you open up the box and find out that it is alive.

      Everything happens at once. We merely perceive it as being sequential

      --
      IANAL, but I've seen actors play them on TV
  7. There's no conflict... by Anonymous Coward · · Score: 5, Interesting

    a formula to determine the roots of any polynomial equation. Does this conflict with Abel's proof that such a formula cannot exist?

    Although an exact solution has been proven impossible for higher orders, this is not the case for numeric solutions.


    No conflict here. Saying that an exact solution does not exist is consistent with saying that numeric solutions do exist.

    A numberic solution is a solution that is "close enough", but not exact. Sort of like saying 2.0000000000000001 = 2. They aren't equal, but for many purposes, they are equivalent.

    1. Re:There's no conflict... by irexe · · Score: 1

      No conflict here. Saying that an exact solution does not exist is consistent with saying that numeric solutions do exist.

      Yeah, except that the author of the paper claims an algebraic solution.

    2. Re:There's no conflict... by Captain+Salty+Pete · · Score: 2, Interesting

      Why should an algebraic solution necessarily be an exact solution?

    3. Re:There's no conflict... by Anonymous Coward · · Score: 0

      indeed.

      I have an approximate solution for all the roots too. here it is:

      root(i) = 0

      I suspect his solution is a little more accurate than mine.

    4. Re:There's no conflict... by kieran · · Score: 2, Funny

      A numberic solution is a solution that is "close enough", but not exact. Sort of like saying 2.0000000000000001 = 2. They aren't equal, but for many purposes, they are equivalent.

      Absolutely - just ask Intel.

    5. Re:There's no conflict... by Anonymous Coward · · Score: 0

      Why do people spell it numberic? It's numeric for god's sake! It's not even pronounced that way. Well, I once had an employee who spelled "floppy disk" "floopy disk". He wasn't joking, this is really how he thought it was spelled. After I corrected him he spelled it right a few times, then forgot and went back to spelling it floopy, thinking that was the correction I gave him. And he wasn't a foreigner either, he was from Massachusetts, with a degree in electrical engineering.

    6. Re:There's no conflict... by Anonymous Coward · · Score: 0
      No! Why do people keep saying it's an infinite series? He uses the first n-1 coefficients of a series, where n is the degree of the equation. That's where he stops, period.

      To be honest I don't understand how it works yet, as that will take a few hours of studying. But it appears that he comes up with a differential equation that has the "roots as solutions". I'm not sure what that means because a differential equation usually has an equation as its solution. If he means the original polynomial equation is the solution to the d.e. - I just don't know at this point - then he has accomplished nothing. But I can't say that for certain until I study it more. Mathematical proofs aren't something you can just read like a novel.

      In any case a differential equation is not an algebraic solution, and (assuming that is what he is doing and assuming his proof is correct) that would be the reason there is no conflict, not because it's a numeric approximation.

    7. Re:There's no conflict... by bonniot · · Score: 3, Informative
      Why should an algebraic solution necessarily be an exact solution?

      Because otherwise it wouldn't be called a solution.

      "Numeric solution" is used here sloppily, it should be "numeric approximation": a number that is close enough to the real solution, or better, a process to progressively come with numbers closer and closer to the solution. In the second case, you can stop the process when you got close enough to the solution, depending on the precision you need.

    8. Re:There's no conflict... by Anonymous Coward · · Score: 0

      Anyone who knows how do spell Floppy Disk is an idiot

    9. Re:There's no conflict... by RWerp · · Score: 1

      Another clarification: Abel (before him, Paolo Ruffini had almost proved it in 1799) proved that there is no general algebraic (using +,-,/,* and roots) formula for a general polynomial of the order higher than four. He did not prove that there are no such solutions. In fact, the Fundamental Theorem of Algebra states that every N-th degree polynomial has N complex roots. There are classes of higher-than-four polynomials which do have algebraic solutions. The exact criterion for this was given by Galois.

      --
      "Long run is a misleading guide to current affairs. In the long run we are all dead." (John Maynard Keynes)
    10. Re:There's no conflict... by mav[LAG] · · Score: 1

      I feel the good in you Anonymous Coward - let go of your hate!

      --
      --- Hot Shot City is particularly good.
    11. Re:There's no conflict... by casuist99 · · Score: 1

      And just ask anyone who's rudely discovered propegating erros in their Matlab programs. Damn floating point numbers!

    12. Re:There's no conflict... by Anonymous Coward · · Score: 0

      How about
      x=.999...
      10x=9.999...

      Subtract x from 10x, then 9x=9.0, so x=1
      1=.999... or just "close enough"?

      Yah, I got yer 1/inf right here.

  8. Better formula by StevenHenderson · · Score: 4, Funny

    TI-89 + solver/roots function = roots of polynomial

    1. Re:Better formula by brufleth · · Score: 1

      Amen.

    2. Re:Better formula by dasmegabyte · · Score: 4, Funny

      Don't mock the TI-89. That's what they're using to serve this article.

      --
      Hey freaks: now you're ju
    3. Re:Better formula by thedillybar · · Score: 1
      >TI-89 + solver/roots function = roots of polynomial

      The TI-89 solver/roots function numerically estimates the roots of polynomials and often takes a very long time to compute an answer, even sometimes reporting that more solutions may exist.

      After this new solution is reviewed, I see no reason why a firmware update wouldn't be available for the 89 that would use this method. And for Mathematica, Maple, Matlab, etc.

  9. Maths == Dutch by Anonymous Coward · · Score: 5, Funny

    Without RTFA I can categorically state that it's all Dutch to me...

    1. Re:Maths == Dutch by penguinoid · · Score: 4, Funny

      RTFA? FTFA, as if anyone could understand it anyways.

      --
      Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
    2. Re:Maths == Dutch by AllUsernamesAreGone · · Score: 4, Funny

      Hmm.. if we can assume that Maths := Dutch then, given that this is Dutch Maths, we can substitute Dutch for Maths to prove that ti is completely Double Dutch...

    3. Re:Maths == Dutch by OneOver137 · · Score: 2, Funny

      Begone with your MathCad symbology! Repent and pronounce allegiance to Mathematica!

    4. Re:Maths == Dutch by Anonymous Coward · · Score: 0

      hmmmmmm double dutch, sounds like some cooool euro porn..

  10. Man does the impossible by gowen · · Score: 5, Insightful

    Popular media today reports that someone has done what is well established to be impossible. Now, which one is more likely:
    i) Abel's proof contains a flaw that generations of extremely talented mathematicians have failed to spot in their years and years of teaching it.
    ii) Student mistaken; popular media talking out of arse.

    (Can't read PDF; slashdotted)

    --
    Athletic Scholarships to universities make as much sense as academic scholarships to sports teams.
    1. Re:Man does the impossible by cs02rm0 · · Score: 1

      (Can't read PDF; slashdotted) PDF of the same name here, presume it's the same document.

    2. Re:Man does the impossible by bs_testability · · Score: 2, Funny

      I'd say it's about 50/50

    3. Re:Man does the impossible by Anonymous Coward · · Score: 0

      Calculating PI exactly is also impossible, yet there are approximations that are very close to it.

      This young students formulae does the same thing.

    4. Re:Man does the impossible by Anonymous Coward · · Score: 0

      iii) Student perfectly correct but has proved something different from what media think he has proved - media talking out of arse.

    5. Re:Man does the impossible by Chris_Jefferson · · Score: 5, Insightful

      Actually, I'm fairly certain it is:
      iii) Student comes up with interesting (and possibly new, I don't know) result of generating infinate series which converges to root of polynomial. Someone (popular media?) believes that this violates Abel's proof (it doesn't, his proof is for finite representations of the roots).

      This has NOTHING to do with Abel, or Godel, or anyone other related theories, as they do not consider the case of infiniate series.

      --
      Combination - fun iPhone puzzling
    6. Re:Man does the impossible by Anonymous Coward · · Score: 0

      Calculating pi is very possible

    7. Re:Man does the impossible by gr8_phk · · Score: 4, Interesting
      iii) Media doesn't understand the difference between an exact solution in radicals and a numeric algorithm. Neither does the public.

      Now I'll RTFA to determine which it really is....

    8. Re:Man does the impossible by the_2nd_coming · · Score: 1

      yay.... a formula for doing something people have been doing for irrational roots since the beginning of time!!!

      --



      I am the Alpha and the Omega-3
    9. Re:Man does the impossible by gowen · · Score: 1

      Wow. That's news. At least to anyone completely unaware of Newton's method. Mathematica can do that in about one nanosecond.

      --
      Athletic Scholarships to universities make as much sense as academic scholarships to sports teams.
    10. Re:Man does the impossible by gowen · · Score: 1
      it doesn't, his proof is for finite representations of the roots
      Representations in radicals. You can solve them if you're prepared to write the roots in terms of elliptic functions, IIRC.

      Anyway, in what sense are series solutions of transcendental equations "news"?
      --
      Athletic Scholarships to universities make as much sense as academic scholarships to sports teams.
    11. Re:Man does the impossible by gowen · · Score: 1

      The fact we can find numerical solutions of polynomials is not what we might call news.

      A method was known to Newton. This method (Power Series) is probably equivalent to something over 100 years old.

      --
      Athletic Scholarships to universities make as much sense as academic scholarships to sports teams.
    12. Re:Man does the impossible by Anonymous Coward · · Score: 1, Insightful

      Indeed, it's trivial to calculate pi exactly. All one needs are a perfect circle and a perfect measuring device. Oh, and a computer that no one will miss while it's trying to find the end of an endless number.

    13. Re:Man does the impossible by WolfWithoutAClause · · Score: 5, Insightful
      Wow. That's news. At least to anyone completely unaware of Newton's method.

      Yeah, but Newton's method isn't guaranteed to converge. This method claims to converge; although you don't get the exact answer in a finite number of steps.

      Whether this method is useful or not, probably depends on how fast it converges and how long it takes to do each step.

      --

      -WolfWithoutAClause

      "Gravity is only a theory, not a fact!"
    14. Re:Man does the impossible by orangesquid · · Score: 4, Funny

      Actually, here's a really easy exact formula for Pi (written in base Pi, just convert the answer to base 10): 10

      --
      --TheOrangeSquid Is it any wonder things seem so awry? We swim in a sea of confusion and don't have to think to survive
    15. Re:Man does the impossible by gowen · · Score: 1
      Yeah, but Newton's method isn't guaranteed to converge
      So use Newton's upper bounding method and then bisection.
      --
      Athletic Scholarships to universities make as much sense as academic scholarships to sports teams.
    16. Re:Man does the impossible by pete-classic · · Score: 2, Funny
      (Can't read PDF; slashdotted)


      I have discovered a truly remarkable proof. which this web server is too small to contain.

      -Peter
    17. Re:Man does the impossible by Anonymous Coward · · Score: 0

      iiii) Anomymous reader tests how easy it is to put a bogus story on the frontpage of slashdot.

    18. Re:Man does the impossible by pixelphsr · · Score: 1

      Reminds me of a kid in my high school trig class who thought he had discovered a method of trisecting an angle using only a compass and straight-edge. This after taking as a challenge the teacher's statement that the Greeks decided 3000 years ago it couldn't be done.

    19. Re:Man does the impossible by Fwet · · Score: 1, Insightful

      Maybe this should be written as 1 ????? 10 base pi should be *approximately pi^2*

      --
      The world is full of people whose notion of a satisfactory future is, in fact, a return to an idealised past. -R. Davie
    20. Re:Man does the impossible by Anonymous Coward · · Score: 1, Insightful

      10 base pi = 1 * pi^1 + 0 * pi^0 ;)

    21. Re:Man does the impossible by gowen · · Score: 1

      Well, the Greek's only thought it couldn't be done. The proof is actually a corollary to Galois's work on the roots of high order polynomials.

      --
      Athletic Scholarships to universities make as much sense as academic scholarships to sports teams.
    22. Re:Man does the impossible by graf0z · · Score: 2, Informative
      i) Abel's proof contains a flaw that generations of extremely talented mathematicians have failed to spot in their years and years of teaching it.

      ii) Student mistaken; popular media talking out of arse.

      iii) Abel's theorem holds ("you cannot solve all polynomial equations by radicals"); student solves all polynomial equations not using radicals but using differential equations and power series; popular media like /. do not understand that this method is known for more than hundred years and that there is no inconsistence.

      /graf0z.

      ps: a link provided by the author himself: solving the quintic

    23. Re:Man does the impossible by WolfWithoutAClause · · Score: 1

      But even then, Newton's method isn't guaranteed to find all the roots is it? AFAIK there is no algorithm for the initial guess.

      --

      -WolfWithoutAClause

      "Gravity is only a theory, not a fact!"
    24. Re:Man does the impossible by Anonymous Coward · · Score: 0

      ii) Student mistaken; popular media talking out of arse

      That should be,
      ii) Student mistaken
      iii) popular media talking out of arse


      As others have pointed out, in this case the answer is (iii). It usually is - the media rarely knows much about that on which it reports, and usually understands it even less.

    25. Re:Man does the impossible by Anonymous Coward · · Score: 0

      that generations of extremely talented mathematicians have failed to spot in their years and years

      You're right: everything there is to invent has been invented, the earth is flat, and, as the extremely talented medical profession still believed less than a century ago, smoking is healthy and a good cure for asthma.

    26. Re:Man does the impossible by grape+jelly · · Score: 2, Insightful

      This is completely untrue. If you look at any number base system, "10" indicates the number of the base. Take base 10 for example:

      1,...,9,10

      or base 8:

      1,...,7,10

      Your argument that 1base(pi) should be pi is ridiculous because 1 in any base (short of base 1, which is equally ridiculous) is really just plain 1. Things only get interesting once numbers exceed the base value.

      Posted at +2 just for fun

    27. Re:Man does the impossible by Anonymous Coward · · Score: 0

      Funny, but that's not base Pi. You're just counting in the same numbering system, but with everything multiplied by 10/Pi.

      But it made me think about whether it's possible to have a non-whole-number-based numbering system. What would the numerals be? It would be really tough to count by 1's using it, because your whole-numbers would have to be represented as fractions in that base. Of course in the case of Pi, you could just use Pi as a numeral. But if you count by fractions or whole multiples of the base, and then you'd have pretty much exactly what the parent has done.

    28. Re:Man does the impossible by a_ghostwheel · · Score: 1

      One can always use simulated annealing algorithms (or similar) to find global minimum. And then go with standard approach.

    29. Re:Man does the impossible by Anonymous Coward · · Score: 0
      You are wrong, he is right. See Mathworld entry on "Base".
      Look down to around:

      Bergman (1957/58) considered an irrational base, and Knuth (1998) considered transcendental bases. This leads to some rather unfamiliar results, such as equating pi to 1 in "base pi," pi = {10}_pi.

    30. Re:Man does the impossible by ConceptJunkie · · Score: 1

      I tried that too in 9th grade. I did find a method to trisect a right angle. :-)

      --
      You are in a maze of twisty little passages, all alike.
    31. Re:Man does the impossible by WolfWithoutAClause · · Score: 1

      Simulated annealing is *really* slow.

      --

      -WolfWithoutAClause

      "Gravity is only a theory, not a fact!"
    32. Re:Man does the impossible by Anonymous Coward · · Score: 0

      Okay, well, I may have been wrong in saying that wasn't base pi, since mathematicians have explored it using exactly that representation. But my questions still stand. Are there other numerals? If it's just 0 and 1, then you've still really done nothing special. You're just counting by pi in a binary numbering system. If that's all irrational-based numbering systems are, then I'd say they're terribly uninteresting.

    33. Re:Man does the impossible by Anonymous Coward · · Score: 3, Funny

      All your base are belong to us!

    34. Re:Man does the impossible by Anonymous Coward · · Score: 0

      Yeah, but how do you count from 0 to 10 (base pi)? 0, 1, 2, 3, uhh...

    35. Re:Man does the impossible by Anonymous Coward · · Score: 0

      You forgot that the "ones digit" is the base to the power zero. In base pi,

      1 -> pi^0
      10 -> pi^1
      100 -> pi^2

      etc.

    36. Re:Man does the impossible by Anonymous Coward · · Score: 0

      iii) Profit! :-)

    37. Re:Man does the impossible by koali · · Score: 2, Insightful

      That's all fine and dandy, but he said 10(base pi

      10(base 2 =2(base 10
      10(base 8 =8(base 10

      etc.

    38. Re:Man does the impossible by Trojan · · Score: 1

      Yes, it claims to converge. However his reasoning in this part doesn't seem to follow much logic. The whole thing actually seems to come down to: first solve an infinite system of equations to get some coefficients, then see if it converges and if it doesn not, go back to the original equation and divide the coefficients by some large number. Of course, dividing the coefficients will change all the earlier calculations, so there is no reason why the result will then converge.

    39. Re:Man does the impossible by Zenzilla · · Score: 1

      I don't think simulated anealing provides you with a guarentee you will find the global minimum. If it is only allowed to run for infinite time there is a %chance the extrema will not be found.

      It will if you let it run for infinite time, but who can do that?

    40. Re:Man does the impossible by fbonnet · · Score: 1

      Life is much simpler in Indiana, where Pi=3.2 (almost)

    41. Re:Man does the impossible by pVoid · · Score: 1

      It must be vacuously true then.

    42. Re:Man does the impossible by JadeNB · · Score: 1

      The theorem on solvability of polynomials dramatically (though reasonably) restricts the methods of solution, so that we don't have anything like all possible finite processes; we're only allowed addition and multiplication (with inverses) and extraction of roots. As another poster pointed out, elliptic integrals (which I suppose you could call finite in some sense) can be used to find roots of polynomials.

    43. Re:Man does the impossible by Anonymous Coward · · Score: 0

      Yeah, but how do you count from 0 to 10 (base pi)? 0, 1, 2, 3, uhh...

      i think that was the joke, but i'll try to reformulate it in terms more familiar to this forum:

      step 1: 0
      steps 2 .. ?: ???
      step ?: Pi!

  11. Re:Damn, 11 Years too late by bootedcat · · Score: 0

    Your "formal language statement" is like http://www.babelcode.org

  12. Re:Damn, 11 Years too late by Alien54 · · Score: 4, Informative
    Unfortunately, the solution requires a knowledge of calculus:

    To do so, we express x as a powerseries of s, and calculate the first n-1 coefficients. We turn the polynomial equation into a differential equation that has the roots as solutions. Then we express the powerseries' coefficients in the first n-1 coefficients. Then the variable s is set to a0. A free parameter is added to make the series convergent.

    The short paper has more details.

    --
    "It is a greater offense to steal men's labor, than their clothes"
  13. Mirror by avalys · · Score: 5, Informative

    Apparently some people can't get to the site, which is funny because I'm having no problem, but here is a mirror.

    The Roots of any Polynomial Equation

    --
    This space intentionally left blank.
    1. Re:Mirror by SydShamino · · Score: 2, Interesting

      Off-topic, but if you are at MIT, then perhaps your requests are routing through Internet 2? Just a thought. Try tracerouting to the site and see what you get.

      --
      It doesn't hurt to be nice.
    2. Re:Mirror by gimpboy · · Score: 1

      I believe we're on internet 2 here, but I cannot get to it. More likely, MIT has a cache and forces all browser requests through that cache. So the document was probably already in the cache before the slashdotting.

      --
      -- john
  14. Its no big deal by moss1956 · · Score: 5, Informative

    The theorem of Abel (or Galois) that is being referred to merely claims that you can't find a general formula built from just the arithmetic operations plus taking nth roots. It has been known for a long time that there is a general formula using elliptic functions.

    The student just used the method of formal power series to solve the equation. This approach dates back at least to Cauchy ~1850 and probably can be found in the works of Euler.

    1. Re:Its no big deal by the_2nd_coming · · Score: 2, Funny

      it is basically like this:

      student gets ahead of teacher's lessons plan...news at 11.

      --



      I am the Alpha and the Omega-3
    2. Re:Its no big deal by NonSequor · · Score: 5, Funny

      Heh, just about everything can be found in the works of Euler. It's like they say, "In Mathematics, it is customary to name things after the first person after Euler to discover them."

      --
      My only political goal is to see to it that no political party achieves its goals.
    3. Re:Its no big deal by proverbialcow · · Score: 5, Funny

      student gets ahead of teacher's lessons plan...news at 11.

      In the U.S., that is a big deal. ;)

      --
      The only surefire protection against Microsoft infections is abstinence. - The Onion
    4. Re:Its no big deal by stromthurman · · Score: 3, Funny

      Naturally, Gauss will have claimed to have discovered this first, but felt it was too trivial to publish.

      --
      I have discovered a truly remarkable sig which this margin is too small to contain.
  15. I have found a replacement for an old cliche by circletimessquare · · Score: 1, Funny

    From now on I will replace the phrase "It's Greek to me," as in, "I can't understand any of that," with the phrase "It's Dutch to me."

    I will do this whenever possible in honor of this Dutch student's obviously impressive, but absolutely inscrutable (to me) breakthrough.

    --
    intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
  16. Very Skeptical by gtoomey · · Score: 0, Redundant

    Abel's proof, and related proofs by Galois, have stood the test of time for 200 years. It would throw most of abstract algebra and modern mathematics on its head if true.

    1. Re:Very Skeptical by Anonymous Coward · · Score: 1, Insightful

      Think about this

      You can do more in 5 minutes mathematically with t Pentium 4 than a mathmatitician 200 years ago could do in a lifetime

    2. Re:Very Skeptical by ezzzD55J · · Score: 1
      IANARealMathematician, but Abel's proof was about a closed-form expression of the solutions to a higher-order polynomial afaik, and that isn't what this result is; although I understand little of what the pdf says, it's clear there are many more equations (deriviatives and differential equations) involved.

      Does this contradict Abel's proof?

    3. Re:Very Skeptical by the_2nd_coming · · Score: 1

      no, it does not. this merely approximates the solution. it is no more impressive than using taylor series to integrate a natural log.

      --



      I am the Alpha and the Omega-3
    4. Re:Very Skeptical by gtoomey · · Score: 2, Funny

      So this is just another numerical method to approximate roots of polynomials? Newton did it 400 years ago. Talk about media beatup.

    5. Re:Very Skeptical by the_2nd_coming · · Score: 1

      I just got modded down..Moderators should not mod something down if they do not understand the subject.

      --



      I am the Alpha and the Omega-3
    6. Re:Very Skeptical by Jagen · · Score: 1

      Umm, you do know maths isnt just about crunching numbers?

    7. Re:Very Skeptical by Anonymous Coward · · Score: 0
      I just got modded down.

      Congratulations.

    8. Re:Very Skeptical by ezzzD55J · · Score: 1

      I doubt it, unless you're talking about calculating, which isn't really what mathematics is (one can help the other, that's about it).

    9. Re:Very Skeptical by Anonymous Coward · · Score: 0

      The opoint being mathmatitions can spend more time formulating ideas and theories and testing them is significantly easier

    10. Re:Very Skeptical by gtoomey · · Score: 1
      The only interesting proof ever discovered by computer was in ternary boolean algrbras.

      And the ONLY thing your computer can calculate are recursively enumerable sets which to be frank are boring.

    11. Re:Very Skeptical by Skavookie · · Score: 1

      Testing a conjecture numerically does nothing to bring one closer to a proof. However, it can sometimes tell a mathematician when pursuing a proof would be pointless by providing counterexamples, but that's only if the mathematician is lucky. The computer can be used as a heuristic to weed out some of the false ideas, but that's about all (as things currently stand; improvements in deduction systems may change this).

    12. Re:Very Skeptical by gtoomey · · Score: 0, Redundant

      And my original post was marked redundant! The moderators are way out of their depth here.

  17. No sample code or algorithm? by mikael · · Score: 4, Insightful

    I'm surprised he didn't include some sample Matlab, Java applet or C code in his paper. It would be useful to have a demonstration that this really works.

    --
    Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
    1. Re:No sample code or algorithm? by Anonymous Coward · · Score: 0

      No, it would have shown that his approach worked only for his (and finitely many) chosen set of samples.

      A mathematical proof demonstrates that the approach works for all cases, and is a *much* stronger result.

    2. Re:No sample code or algorithm? by Anonymous Coward · · Score: 0

      That would be patented, of course. Remember, math is science, but software algorithms are business.

    3. Re:No sample code or algorithm? by gowen · · Score: 1

      Here's some sample Mathematica code

      Roots[polynomial[x] == 0,x]

      Hey, whaddya know? Mathematica can already find numerical solutions of polynomials.

      --
      Athletic Scholarships to universities make as much sense as academic scholarships to sports teams.
    4. Re:No sample code or algorithm? by PiGuy · · Score: 1

      As a matter of fact, he did. But rather than using a language such as Matlab, Java, or C, he used the a wonderfully versatile and universal language called "math". Seriously though, this is one of the most straightforward, algorithmical, descriptions I've ever seen in a math paper. I'm not even a math major and I can follow it (or at least theoretically should be able to, given my background in diff eqs and linear algebra). Would that more math papers be written like this....

    5. Re:No sample code or algorithm? by ricotest · · Score: 1

      Dutch people can't afford Matlab, you insensitive clod!

    6. Re:No sample code or algorithm? by Anonymous Coward · · Score: 0

      I'm surprised this was modded as Insightful.

    7. Re:No sample code or algorithm? by BlowChunx · · Score: 1

      And here's what Matlab knows:

      >> help roots

      ROOTS Find polynomial roots.
      ROOTS(C) computes the roots of the polynomial whose coefficients
      are the elements of the vector C. If C has N+1 components,
      the polynomial is C(1)*X^N + ... + C(N)*X + C(N+1).

      See also POLY, RESIDUE, FZERO.

    8. Re:No sample code or algorithm? by Darth_Burrito · · Score: 2, Interesting

      Wrong. A mathematical proof demonstrates to (some) other mathematicians that the approach works for all cases. Meanwhile, this translates to the rest of the world as "the math guys say they think this works." To many of us, this is roughly equivalent to hearing someone say, "Jim thinks he has fixed the mail server."

      To lend validity to either of these statements, you need to add understandable, accessible evidence. Jim thinks he fixed the mail server. It's been up and running for 30 days without any problems. Here is a proof showing how to numerically solve any polynomial equation and here's a program that runs the algorithm and shows several examples that work.

    9. Re:No sample code or algorithm? by Trojan · · Score: 1

      Uhm, no this paper is not at all straightforward. I would be really surprised if it can be made to work for quadratic equations.

    10. Re:No sample code or algorithm? by ByteSlicer · · Score: 1

      There are no software patents in Europe (yet, and hopefully never). And if I'm not mistaken, the Dutch got rid of all patents.

  18. I am old by TheVidiot · · Score: 2, Interesting


    This is yet another reminder of how long it has been since I was in university....

    I can recognized the names of the equations involved, but that's about it...

    In many ways, that illustrates how useful the knowledge has been over the years!

  19. Re:/.ed after 4 comments NOT by Anonymous Coward · · Score: 0

    What are you smoking, The site is fine,

  20. I guess this is obsolete now... by Paster+Of+Muppets · · Score: 4, Funny

    LISTER: Yeah, the Skutters managed to smuggles something out of the medi-lab for us, y'know that stuff that helps impotent guys put the zest back in their love lives?

    KRYTEN: 'Boing!', the virility enhancement drug!?

    LISTER: That's the stuff, and we've Mickey Finn'd their drinks.

    RIMMER: Within seconds, you're harder than a quadratic equation, and, it doesn't wear off for seven hours.

    KRYTEN: For seven hours those guys are going to be like catapults!

    Red Dwarf, Series 8, Episode 6

    --
    Due to lack of disk space this user has been discontinued
    1. Re:I guess this is obsolete now... by Ignignot · · Score: 1

      Scientific progress goes boing??

      --
      I submitted this story last night, and it didn't get posted.
  21. Re:run away! by slavemowgli · · Score: 4, Informative

    That's dutch, not german.

    --
    quidquid latine dictum sit altum videtur.
  22. Re:run away! by Peyna · · Score: 0, Redundant

    It's not German, it's Dutch (Nederlandic?)

    --
    What?
  23. Rule of equations in school by Kohath · · Score: 5, Funny

    The rule of equations (at least in school) is:

    The more complicated the equations for the math problem looks, the more likely the answer is 1.

    1. Re:Rule of equations in school by alcmena · · Score: 1

      Or zero. I used to have a prof who would occationally slip in a multiply by zero somewhere in the equation for one reason or another.

    2. Re:Rule of equations in school by PureCreditor · · Score: 2, Funny

      we as /.-ters all know that as complexity of the problem reaches infinity, the answer approaches 42. =)

    3. Re:Rule of equations in school by Mignon · · Score: 4, Funny

      When I was teaching calculus I made an exam where every answer was 2. I was sort of amused watching the students faces as they at first started doubting themselves, then slowly got the "joke."

    4. Re:Rule of equations in school by GoofyBoy · · Score: 1

      Or its pi or 1/2 pi or the surface area of some sphere.

      I hated 2nd year calculus.

      --
      The surprise isn't how often we make bad choices; the surprise is how seldom they defeat us.
    5. Re:Rule of equations in school by dustman · · Score: 1

      Time for some mega nerdiness: I was captain of the math team when I was in high school.

      When you submitted answers for the questions, only the answer mattered. You didn't need to "show your work".

      You wouldn't normally say the answers were "often" 0 or 1, since it was only a few percent of the time. But it was often enough that I would guess 0 or 1 on a problem I couldn't solve, and occasionally get a few points that way.

    6. Re:Rule of equations in school by hawkeyeMI · · Score: 1
      You are evil.

      I guess you could have made every answer zero, and that might have been more evil.

      --
      Error 404 - Sig Not Found
    7. Re:Rule of equations in school by revscat · · Score: 4, Insightful

      Time for some mega nerdiness: I was captain of the math team when I was in high school.

      Feh, screw that "nerdiness" crap. Good for you. Math is a powerful tool, worthy of dedication. I wish I were better at it, and respect those who are. I think being captain of the math team is far and away a better thing than being the captain of the freakin football team.

    8. Re:Rule of equations in school by alcmena · · Score: 1

      If you want to be a real ass, make all answers come out to 7337.

    9. Re:Rule of equations in school by ralmeida · · Score: 2, Funny

      Shame on you. It should've been 42.

      --
      This space left intentionally blank.
    10. Re:Rule of equations in school by myndzi · · Score: 1

      I had a Science teacher in high school who would put subtle jokes into his test. He said he did it so he could tell about how far the students were. He had to stop doing it, because the students stopped getting the jokes.

      Sad, really...

    11. Re:Rule of equations in school by Clueless+Moron · · Score: 1
      When I was teaching calculus I made an exam where every answer was 2. I was sort of amused watching the students faces as they at first started doubting themselves, then slowly got the "joke."

      Now, if you were a real bastard, you would have made the last question come out to 1 instead.

      Then sit back and watch as all the students frantically try to figure their "mistake" on that question.

    12. Re:Rule of equations in school by Anonymous Coward · · Score: 0

      That would never work on me. I never make mistaes! I always go right through all the questions and check them when I'm done.

    13. Re:Rule of equations in school by Alsee · · Score: 1

      Even better, have the last question come out to 1, and weight that question as 50% of the test. That way anone who fills in 2 for it without doing the work will fail. Heh.

      -

      --
      - - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
    14. Re:Rule of equations in school by HikeFanatic · · Score: 2, Funny

      I had one math professor who decided to include "Prove or disprove: Fermat's Last Theorem" as a bonus question on an exam.

      The class knew he was joking, but some decided to try it anyway...

    15. Re:Rule of equations in school by Obfiscator · · Score: 1
      I think being captain of the math team is far and away a better thing than being the captain of the freakin football team.

      I would disagree. I think they are both good things, and why not? Being captain of the football team means leading a group of physically large people with type A personalities. Not an easy task.

      On the other hand, being captain of the math team means leading a group of very smart people who are likely to nitpick and not forgive any mistake you make. Not an easy task, either.

      Then again, maybe you're a born leader and everyone likes you, so you'll never have a problem either way.

      --
      "Nothing shocks me. I'm a scientist." -Indiana Jones
    16. Re:Rule of equations in school by Anonymous Coward · · Score: 0

      Now, if you were a real bastard, you would have made the last question come out to 1 instead.

      Nah, if I were taking such a test, I would skip down and check the last one to make sure the trend followed to the end. So make it the second or third to last.

      Of course I probably still wouldn't have the nerve to just write "2" for all of them...

    17. Re:Rule of equations in school by judo_badger · · Score: 1

      "Prove or disprove: Fermat's Last Theorem" = yes

    18. Re:Rule of equations in school by kcdoodle · · Score: 1

      Nice hitchhikers guide to the galaxy reference!

      I cannot believe my fellow geeks have not caught it yet.

      I live the greatest adventure anyone could wish for. - Tosk the Hunted.

      --

      - I live the greatest adventure anyone could possibly desire. - Tosk the Hunted
    19. Re:Rule of equations in school by pdxmac · · Score: 1

      I teach HS math, and I used to do things like that.

      Then I remembered the point of the test wasn't my own amusement...

    20. Re:Rule of equations in school by brucehoult · · Score: 1

      When I was teaching calculus I made an exam where every answer was 2

      It would be funnier if they were all 42.

  24. Re:run away! by Anonymous Coward · · Score: 0

    sorry to be that crude, but it's not German - it's Dutch .. that's quite a difference ..

  25. Isn't it an approximation method? by hankwang · · Score: 5, Interesting

    I am a phycisist, not a professional mathematician, and I didn't understand all steps in the whole paper. However, the author mentions a series expansion with an infinite number of terms in equation (6), although only the first n terms are ever used in defining the solution. That sounds a bit strange to me. In any case, the exact solution for a third-order equation (n=3) involves lots of cube roots and I don't see those anywhere, which also suggests that it's all about an approximation method.

    1. Re:Isn't it an approximation method? by Leadhyena · · Score: 5, Insightful

      You got it... instead of a solution by radicals (which Abel's proof shows does not exist for general polynomials with degree 5 and higher) he takes it into differential equations and creates a powerseries, which essentially gives an approach to the real number root, which doesn't necessarily have a radical decomposition. Plus, the proof looks like a lot of handwaving at a cursory glance. I'm more inclined to believe that this is a wash.

    2. Re:Isn't it an approximation method? by the_2nd_coming · · Score: 1

      sounds more like he learned the usefulness of infinite series and decided to apply it to polynomials. Mathematicians are lazy, I am sure you are right that this is either a wash or more difficult than other methods of finding the roots.

      --



      I am the Alpha and the Omega-3
    3. Re:Isn't it an approximation method? by famebait · · Score: 2, Informative

      I thought the issue with older methods was that although they converge easily on any root, it becomes non-trivial to find out where to start in order to hit some of the roots when you get to the higher orders. If this method reliably finds them efficiently and is suitable as an automated algorithm, that is certainly a useful result, though it might be not exactly revoloutionary to the field of mathematics.

      --
      sudo ergo sum
    4. Re:Isn't it an approximation method? by the_2nd_coming · · Score: 1

      if it is useful, then it most certainly is not revolutionary...it is more like some one just kinda over looked an application of well known theorems. the news makes it sound like he will be the next fields medal winner.

      --



      I am the Alpha and the Omega-3
    5. Re:Isn't it an approximation method? by novakyu · · Score: 1

      That's what I thought, too--so, how is this anything new? A simple binary search algorithm would do the job as well (er, if you know where to look for the zeros).

    6. Re:Isn't it an approximation method? by Trojan · · Score: 1

      Exactly. And actually, you just proved that his method must contain a flaw: all the calculations are performed within the real numbers (even at the point where he needs to calculate the root of an equation of degree n-1, since obviously one should use recursion to get at that one). So he always finds a real-valued root. Maybe someone can try his method on x^2+1=0.

      And another argument: even if the whole thing is algebraically correct, and the final result actually does converge, the method would still require the above-mentioned recursion to get an approximation of approximations of approximations (etc..) of the desired coefficients.

    7. Re:Isn't it an approximation method? by Trojan · · Score: 1

      It's all caused by a press statement of a "Hogeschool" which is a level below academia. They don't have research-level mathematics teachers there to tell the student (and the school) that it's a nice try (and nothing more).

    8. Re:Isn't it an approximation method? by Anonymous Coward · · Score: 0

      Bah. If proof by hand waving worked for my professors it will work for me! Until the bridge collapses in which case I will be performing a proof by absence from the country...

    9. Re:Isn't it an approximation method? by Rich0 · · Score: 1

      So, I wonder what the approximate series is to solve the polynomial equation:

      x - 1 = 0

      I was hoping to read the article and answer my own question, but I only have an MS in Chemistry and a minor in mathematics...

      It lost me on the second sentence (taking the first 0 derivatives of (x-1) to -1 - whatever that is supposed to mean). In all fairness, for a larger degree polynomial it might say take the first 2 derivatives of (x^3-2x^2+3x-2) to -2. However, that still doesn't make any sense. Even if you keep the s generic it doesn't make sense - they suggest taking d^n(x(s))/ds^n, but none of the terms in the equation depend on s except the last, and d^n(s)/ds^n is pretty trivial...

      I'm sure I'm just missing the intent of the authors...

    10. Re:Isn't it an approximation method? by Rich0 · · Score: 1

      I'm not sure how root-finding algorithms do this in general, but the roots lie between the maxima and minima, which are the roots of the first derivative. Those roots lie between the roots of the 2nd derivative, and so on. So, if you have a 150 degree polynomial, its 150 roots lie between the 149 roots of its 1st derivative. You can see that you can solve this recursively.

      Of course, there are the two roots outside the maxima/minima, but those are easy to find. Just anchor one side of the binary search at the outside maxima, and then move away from it until you get a sign change in the function. Then you are flanking the root and can find it.

  26. The paper is in english by Anonymous Coward · · Score: 0

    Enough with the english jokes already. The paper itself is in english and it is only three pages. Now go read it you math people!

  27. Re:run away! by jellomizer · · Score: 1

    Actually it is dutch.

    Temporarily not available!

    This site is not temporarily available because of too much
    data-verkeer.

    --
    If something is so important that you feel the need to post it on the internet... It probably isn't that important.
  28. Re:run away! by Nadir · · Score: 0, Redundant

    In fact that is Dutch

    --
    --
    The world is divided in two categories:
    those with a loaded gun and those who dig. You dig.
  29. Re:run away! by gvdkamp · · Score: 1

    Sorry to scare you even more. This isn't german but dutch. Now you know why you have a saying about people talking double-dutch ;-)

  30. Re:run away! by Anonymous Coward · · Score: 0

    thats not german, its dutch! and dutch is not even like german - i mean no(t many) germans understand dutch out of the box...

  31. /.'ed, try this Coraled URL using another source by arnoroefs2000 · · Score: 2, Informative
  32. Re:run away! by dan+dan+the+dna+man · · Score: 0, Redundant

    I think you'll find it's Dutch - didn't even RTFS(ummary)? ;)

    --
    I don't read your sig, why do you read mine?
  33. Re:run away! by Svet-Am · · Score: 1

    German?

    Umm, no. This is DUTCH. That's why he's from the Netherlands, where the people are called DUTCH and they speak DUTCH.

    Dutch, German == Germanic Tongues

    Dutch != German

    Niederländisch ist nicht deutsch!

    --
    [move .sig! for great justice, take off every .sig!]
  34. learn to read by Errtu76 · · Score: 0, Redundant

    WTF does german have to do with it?? Since it's in Dutch! Comparing dutch with german is a huge insult for most Dutch people, including me. Just because it might look/sound the same to foreigners, it's not. The same goes for portugesespanish.

    1. Re:learn to read by someme2 · · Score: 0

      Comparing dutch with german is a huge insult for most Dutch people, including me. Just because it might look/sound the same to foreigners, it's not. The same goes for portugesespanish.

      Comparing portugese to spanish is a big insult to Dutch people?

      --
      You can attach boosters to anything. It just costs more. -
      Anonymous Coward on Sunday November 07, @12:26PM
    2. Re:learn to read by Anonymous Coward · · Score: 0

      Most Dutch people, including me, won't really mind if you mistake Dutch for German... "huge insult" is certainly not true for most of the Dutch.

      Plus, it could be the case that what was meant in the original message was "well, I know *German* can be scary, but look at this, this is even worse!". ;)

    3. Re:learn to read by e-Trolley · · Score: 0

      It's a huge insult for most german people, too ;) BTW: stay away from our Highways :p

    4. Re:learn to read by Anonymous Coward · · Score: 0

      No offense, I'm German and I've always found Dutch to be a close linguistic relative to German "Platt", the fading dialect which was spoken in north-western Germany. There is no remarkable natural border between our countries and people living close to the border have always been influenced more by the culture of the region than their nation states. It's only logical that their languages mixed somewhat.

    5. Re:learn to read by Errtu76 · · Score: 1

      only if you stay away from our beaches! :P

    6. Re:learn to read by Errtu76 · · Score: 1

      You're right. *huge* insult is not true. But i feel kinda obligated to protest if somebody mixes up the two.

    7. Re:learn to read by Errtu76 · · Score: 1

      But .. but .. it's so .. unnatural! Why do you insist on using capitals in the middle of a sentence? :)

      Thanks for the "Platt" info though. I'm going to look into it.

    8. Re:learn to read by Anonymous Coward · · Score: 0

      How do you tell if someone took more than three attempts to get a drivers license? He gets a yellow license plate.

      I'm looking forward to your reply. I've always wondered what stereotypes are applied to us.

    9. Re:learn to read by Anonymous Coward · · Score: 0

      English used to, too.

    10. Re:learn to read by Anonymous Coward · · Score: 0

      The problem comes that the German word for German is "Deutsch".

      This looks and sounds a lot like "Dutch" does in English.

      This is why the Pennsylvania Dutch heritage, is in fact German. (Who settled in PA)

  35. Polynomials of degree 5 are NOT solvable by Anonymous Coward · · Score: 0

    Alright, a subject I am familiar with! As a math major, I know that polynomials of degree 5 are not solvable in terms of radicals, in general. This is Galois Theorem. It also ties in quite well in other areas of mathematics, not just algebra.

    Special cases are solvable, but for the general equation x^5 + ax^4 + bx + cx + dx + e = 0, the general solution for x cannot be expressed in terms of radicals. Approximating solutions, however, is a completely different matter.

  36. My brain seems to have shut down. by D_Nice · · Score: 3, Funny

    While I was in HS and College, this would have made so much sense to me. Looking at all the work behind it just makes my head hurt now. I think I replaced my math knowledge with coding ability.

    --
    Technology's a battle between companies producing more idiot-proof systems and nature producing bigger and better idiots
    1. Re:My brain seems to have shut down. by Anonymous Coward · · Score: 0

      likewise. everything that i needed to know about math can [pretty-much] be broken down to calc I [the part that bored me to sleep] and a compiler, these days. and I R A professional 'Scientist' [and our research group's 'math guru'.

  37. Re:run away! by Anonymous Coward · · Score: 0

    Just to be a complete A-hole stickler. But that is not german, it is dutch.

    Tijdelijk niet beschikbaar == Temporarily Unavailable.

    Sorry, I had to do it.

    Disclaimer: I am half Dutch (Belgian actually).

  38. Easy! by Bluesman · · Score: 3, Funny

    (1) Let Sa be the set of all possible roots of polynomial equations.

    (2) From [1], we have determined that the correct roots, a1...an, exist in Sa.

    (3) Let the set Sb be the set that contains only a1...an.

    (4) The intersection of sets Sa and Sb will thus be the roots of the polynomial equation.

    Therfore, we derive the formula:

    Sa ^ Sb = roots

    --
    If moderation could change anything, it would be illegal.
    1. Re:Easy! by slimak · · Score: 1
      so, Sa = C (set of all complex #)
      and Sb = {a1,...an}
      so Sa ^ Sb = Sb

      now if I could only find Sb:)

    2. Re:Easy! by daveashcroft · · Score: 5, Funny

      You seem to have forgotten the final step:

      5) Profit!

      (awaits an ass-whooping by the mods)

    3. Re:Easy! by Anonymous Coward · · Score: 0

      (1) Let Sa be the set of all possible roots of polynomial equations.

      (2) From [1], we have determined that the correct roots, a1...an, exist in Sa.

      (3) Let the set Sb be the set that contains only a1...an.

      (4) The intersection of sets Sa and Sb will thus be the roots of the polynomial equation.

      Therfore, we derive the formula:

      Sa ^ Sb = roots


      (5) Profit???
    4. Re:Easy! by Anonymous Coward · · Score: 0

      Pi is a complex number but not a root of any polynomial equation, so Sa can't be equal to C.

    5. Re:Easy! by D_Nice · · Score: 1

      Actually, it would work more like this toward the end:

      (5) ?????
      (6) Profit

      _

      --
      Technology's a battle between companies producing more idiot-proof systems and nature producing bigger and better idiots
    6. Re:Easy! by slimak · · Score: 1

      Pi is irrationat, not complex. In addition, it is the root of the following 1st order polynomial equation
      x-pi=0

  39. Re:Heh. by sremick · · Score: 1

    Agreed. I can remember back in Jr. High writing a program in GW-BASIC (!!!) that would factor any polynomial equation I threw at it. No use for cheating as the teachers wanted to see your work, but was great for checking my answers.

    Maybe if I could understand Dutch I'd get why this is a big deal.

  40. Derivatives? by ScottyB · · Score: 1, Interesting

    IANAM, so I cannot really decipher the proof with any accuracy, but like any good Slashdot reader I will not hesitate to state my uniformed opinion.

    It strikes me that there may be a problem since taking derivatives is involved. It seems like one might lose some valuable information by using derivatives to solve the equation since the zero-order term is lost.

    Can a trained mathematician enlighten us on how this proof works?

    1. Re:Derivatives? by Anonymous Coward · · Score: 0

      What [i]uniform[/i] would that be?

    2. Re:Derivatives? by Anonymous Coward · · Score: 0

      IANAM but like my colleague above IAAP.

      You lose nothing when you differentiate, the equation remains true. However you cannot integrate and return to the original function since there is an unknown offset c.

      That however isn't really a loss as such.

    3. Re:Derivatives? by kryptkpr · · Score: 1

      I'm not a trained mathematician, but I still mostly understand the proof. It works by converting the n-degree-polynomial into an n-degree-differential equation, the solutions of which are identical to the original polynomial equation. A power series (for those rusty, this is an infinite sum) is then used (and made to converege with the use of a free parameter .. adding an infinite number of things does not always yield a finite sum, but sometimes it does) to approxomate the solutions.

      There's really nothing new here..

      --
      DJ kRYPT's Free MP3s!
    4. Re:Derivatives? by Skavookie · · Score: 1

      Ok, here's an explanation that's not formally correct but gives the general idea. The method is basically to find the derivatives of x with respect to the constant term and then use these derivatives to form a Taylor series expansion of x in terms of the constant term. In other words, the author finds the root x as a function of the constant term, effectively reintroducing that term in the end.

  41. Re:run away! by alyosha1 · · Score: 1

    "Currently not available. The site (blah).pdf is not currently available due to too much data traffic." Dutch can be a bit gutteral, but the dialects spoken in Belgium are a lot softer, and less hard on the throat!

  42. Re:run away! by Koohoolinn · · Score: 1

    Temporary unavailable This site http://www.dse.nl/~geertjan/Publikatie/The-roots-o f-any-polynomial-equation.pdf is temporary unavailable because of too many data traffic.

    --
    Deze sig is in 't Nederlands geschreven.
  43. Re:run away! by ice2cold · · Score: 0, Redundant

    Sir, The language you are writing about is Dutch. The translation follows: "This site is at the moment not reachable because of too much traffic. I hope that helps you all out a little. Very respectfully, Ice2cold

    --
    Whoever said the pen is mightier than the sword, obviously didn't encounter automatic weapons. General Douglas McCart
  44. Re:run away! by Anonymous Coward · · Score: 0

    to the guy who got upset about the german confusion saying dutch is NOTHING like german...go die in a corner somewhere, I am fluent in german and can understand most dutch, yes there are differences, but they are not NOTHING alike.

  45. europe by nnnneedles · · Score: 5, Funny

    The present:
    european academic finds solution to very hard problem.

    2 years later:
    a) americans find way of turning said solution into entertainment technology and make billions of dollars.b) European academic still unemployed and eating pasta all week.

    We need more GREED in europe.. :/

    --
    Will code a sig generator for food
    1. Re:europe by stud9920 · · Score: 1

      1 year later The RIAA has the method forbidden. The Dutch guy is still poor, but at least not in jail.

    2. Re:europe by Anonymous Coward · · Score: 0

      70% Funny?
      30% Overrated?

      Mod parent insightfull. He's damn right!

    3. Re:europe by vidnet · · Score: 2, Funny

      Phh! Spammers are making billions on rooting already!

    4. Re:europe by forii · · Score: 1

      We need more GREED in europe.. :/
      You have plenty... it's just concentrated in your government(s).

    5. Re:europe by Anonymous Coward · · Score: 0

      Phh!

      Eh?

  46. Those Dutch by Anonymous Coward · · Score: 0

    spelling 'teh' backwards all the time.

  47. DOH! Slashdot ate my superscripts! by Anonymous Coward · · Score: 0

    It seems that slashdot does not like the ASCII characters for "cubed" and "squared." So just replace what I wrote with x^5 + ax^4 + bx^3 + cx^2 + dx + e = 0, and what I stated previously still stands.

    1. Re:DOH! Slashdot ate my superscripts! by Anonymous Coward · · Score: 0

      You seem to live in a different universe than me. There are _no_ ASCII characters for "cubed" and "squared". ASCII = Unicode 0x0000-0x007f, superscript 2 = Unicode 0x00b2, superscript 3 = Unicode 0x00b3.

    2. Re:DOH! Slashdot ate my superscripts! by Anonymous Coward · · Score: 0

      You're half right.

      ASCII was expanded from 128 to 256 characters long ago. Try 0xFD (decimal 253) for squared. You are right that cubed is not in this range.

    3. Re:DOH! Slashdot ate my superscripts! by Superjhemp · · Score: 1
      Try 0xFD (decimal 253) for squared.

      Nope, that's a y with an acute accent (ý)

    4. Re:DOH! Slashdot ate my superscripts! by Anonymous Coward · · Score: 0

      Use Alt-253, not Alt-0253. =P

  48. Obvious Hoax by wondafucka · · Score: 4, Funny

    I mean, come on. A Dutch student?

    1. Re:Obvious Hoax by troon · · Score: 2, Insightful

      Hey, the Dutch are dudes.

      • Huygens
      • I'm sure there are others, too
      --
      Ydco co ,df C erb-y go. a Ekrpat t.fxrapev
    2. Re:Obvious Hoax by Leto2 · · Score: 1

      Hey they exist!!!!! I was one for eight (8) friggin' years. (and I have no clue how to read that paper, by the way, it's all Greek to me)

      --
      <grub> Reading /. at -1 is like driving through Cracktown in a convertible that is stuck in 1st
  49. Formula for hard cash by Fuzzums · · Score: 1

    1. Solved math problem of several centuries old
    2. ...
    3. PROFIT ;)

    Can somebody give me the universal formula for 'step 2'?

    --
    Privacy is terrorism.
    1. Re:Formula for hard cash by Arimus · · Score: 1

      Just patent the idea above and leave step 2 to some bored student... then when they make money from 2 wave your patent and get 3.

      --
      --- Users are like bacteria -> Each one causing a thousand tiny crises until the host finally gives up and dies.
    2. Re:Formula for hard cash by Anonymous Coward · · Score: 0

      That proof is left for the student...
      - Famous last word on text book

  50. Re:/.'ed, try this Coraled URL using another sourc by Anonymous Coward · · Score: 0

    COmes up slower than the origional site...!

  51. what no TeX? by Carbon+Unit+549 · · Score: 2, Insightful

    From the looks of the ugly type, he must of used word. Oh the horror. The horror.

    --

    nohup rm -rf ~/. >& zen &

    1. Re:what no TeX? by Anonymous Coward · · Score: 0

      From the looks of your grammar, English must not be your mother-tongue.

    2. Re:what no TeX? by Anonymous Coward · · Score: 0
      From the looks of the ugly type, he must of used word. Oh the horror. The horror.

      That's fine, but I just don't get the part when he raises 179 to the power of th.

    3. Re:what no TeX? by Anonymous Coward · · Score: 0

      Actually, the PDF file was created by "GNU GhostScript 7.06" (at least that's what it says in the file header).

      I think that makes Word rather unlikely, and creates some suspicion of a certain OS OS where TeX clones are rumored to be used from time to time.

      Anyway, if it was created in word it would look *much* better.

    4. Re:what no TeX? by troon · · Score: 1

      he must of used word

      One advantage of Word over TeX: its grammar checker would have warned him about that error.

      --
      Ydco co ,df C erb-y go. a Ekrpat t.fxrapev
    5. Re:what no TeX? by Anonymous Coward · · Score: 0

      "Must of"? What is that? Do you mean "must have"?

      OF IS NOT A VERB.

    6. Re:what no TeX? by ols22 · · Score: 1
      he must of used word
      One advantage of Word over TeX: its grammar checker would have warned him about that error.
      in defense of the original poster, word/grammar checkers are not used for posting comments to /.
    7. Re:what no TeX? by ArsSineArtificio · · Score: 1
      From the looks of the ugly type, he must of used word. Oh the horror. The horror.

      No, that's a typewriter from 1971, honest :-)

      --
      All employees must wash hands before seeking equitable relief.
  52. 11 Years too late by blibloblu · · Score: 4, Funny

    Yeah, I proved that 11 years ago. Unfortunately for the rest of humankind, the margin was too small for me to write everything down.

  53. Re:run away! by stud9920 · · Score: 1

    Dutch is not harsh at all, it's the most floppy, softened germanic language there is out there.

    Dutch:German::Portuguese:Spanish

  54. Warning, secure your linux boxes! by Anonymous Coward · · Score: 0

    Due to a reacent mathmatical breakthrough it is now possible for anyone to gain ROOT

  55. There's a big by Anonymous Coward · · Score: 0

    difference between finding one root and finding all roots numerically.

    1. Re:There's a big by Anonymous Coward · · Score: 0
      difference between finding one root and finding all roots numerically.
      Find one root a.
      Divide polynomial by (x-a).
      Wash, rinse repeat.
    2. Re:There's a big by miskatonic+alumnus · · Score: 1

      Nope. You don't want to do it that way. Since there is an error in your computation of a, your quotient poly has different roots than the original poly. Furthermore, the roots of polys are very sensitive to changes in the coefficients.

  56. This doesn't seem likely by 808140 · · Score: 5, Interesting

    The article in question is slashdotted, but my guess is either that this is media sensationalism, or the writeup is claiming something different from the student -- it seems like perhaps a new way to numerically approximate polynomial roots has been discovered.

    However, from what I remember, Abel's theorem was proven using Galois Groups and Field extensions. This implies that what it actually proves is that analytical solutions using a particular set of functions -- in particular, the field operations (addition, subtraction, multiplication, division by non-zero) extended to include radicals (square, cubic, etc roots), composed in any way possible (as in a ruler and compass construction proof) cannot possibly generate an analytical formula depicting the solution for polynomials of order greater than 4.

    Does this mean that an analytical formula using other functions is impossible? Not at all. Trivially, I will define a function called, say, omega, which, given a n-dimensional complex vector, gives a solution to one of the roots of the function a_n * x^n + a_(n-1) * x^(n-1) + ... + a_0 where a_n are the elements of said vector. Then, by repeated application of omega and polynomial long division, I have an analytical solution to any polynomial, of any order, in complex space.

    Clearly, this solution is analytical in the sense that it a) provides an exact solution and b) is algebraic in nature. However, it isn't useful, because it depends on a function (omega) which cannot itself be defined analytically in terms of other functions (or at least, not ones we know how to compute).

    The reason Abel's proof is so important is because it deals with the 4 fundamental operations that polynomials themselves use (the field ops) and adds radicals, which are inverse ops to the building blocks of polynomials themselves. So it essentially says, we cannot use the functions that we constructed the polynomial with to solve it.

    Now, my omega function may seem a little bit contrived to non-math types, but actually a large number of functions are arbitrarily defined this way. Logarithms are a good simple example. An analytical formula for the likes of log n wouldn't be possible either, and yet we study logarithms without having an express analytical means of calculating them.

    What you should ask yourself is, what does analytical mean, anyway? It really isn't useful (or correct) to say that no analytical solution exists unless you explicitly restrict what particular set of 'basic' functions/operators the analytical solution can contain. In Abel's case (and it's a beautiful proof, by the way) he uses the field operators plus radicals. But what if you added logarithms into the mix? Exponential functions?

    It's impossible to say. If you don't restrict your base, you open yourself up to the attack that I just used with the omega function (which certainly exists, after all, I just defined it.)

    1. Re:This doesn't seem likely by e-Trolley · · Score: 0

      Excellent! Thx for your post 808140, that makes many things much clearer.

    2. Re:This doesn't seem likely by Daniel+Boisvert · · Score: 1

      Damn, that actually made sense.

      Thank you!

      You don't by any chance teach math somewhere in New England, do you? I'm contemplating going back to school.. ;)

    3. Re:This doesn't seem likely by 808140 · · Score: 1

      Rereading my post, it seems I should have said an n+1 dimensional complex vector, as an nth order polynomial has n+1 terms...

      Ah well... You can't win em all :)

    4. Re:This doesn't seem likely by miskatonic+alumnus · · Score: 2, Informative

      It's not quite that simple. Your function isn't well-defined. Furthermore, I believe you would need the Axiom of Choice just to show that such functions exist.

    5. Re:This doesn't seem likely by DrEasy · · Score: 1

      (sorry if I am missing something, my math is rusty)

      But the logarithm function isn't all that magical, since you can express it as the integral of 1/x. So do you mean that integrals aren't part of an analytical solution? (I guess there must be a proof somewhere stating that you can't calculate all integrals using analytical solutions?)

      --
      "In our tactical decisions, we are operating contrary to our strategic interest."
    6. Re:This doesn't seem likely by 808140 · · Score: 1

      As I said, by analytical we mean an algebraic composition of a restricted set of functions and operators. In Abel's proof, he uses extensions on fields to demonstrate, essentially, that it is impossible to solve an arbitrary polynomial by radicals. This is important because radicals are the inverse functions that solve simple polynomials -- the inverse of x^n is the nth root. So essentially what Abel says is, using addition, subtraction, multiplication, division by non-zero, and any radical functions, it is impossible to derive a general formula for nth order polynomials where n > 4. This is relevant because these are the operations used to construct the polynomial, plus radicals (which are usually used, in simple cases, to invert polynomials).

      As for integrals, you can take the definite integral of 1/x dx from 1 to n as the definition of log. It isn't the only one (the trivial definition is just that it's the inverse of e^x, but using an integral definition allows you to use your knowledge of Calculus to derive some other interesting properties of logarithms, just as the inverse function definitions allow you to show simple stuff like log(ab) = log(a) + log(b) and the like.)

      But again, in light of our defining log n using integrals: what does it mean to be analytical? We say that you can integrate 1/x analytically, but if I were to tell you that log is defined in terms of the integral of 1/x, would you still say that?

      That was the point of my (rather contrived) omega function thing. If I don't restrict the body of operations/functions I am using to construct my analytical solution, I can simply define my solution and say it exists, assuming I can prove it is well-defined.

      If you restrict yourself to the "simple" functions like +,-,*,/, roots, trig functions, exponential functions -- all the stuff you learned in high school algebra -- it isn't particularly hard to show that lots and lots of integrals don't have analytical solutions.

      In fact, delving deeper, there are a large class of integrals that are not even computable if you use the rather flawed but somewhat simpler Riemann integral to compute them. Lebesgue Integrals are much more general (but unfortunately, rather more complex to motivate).

    7. Re:This doesn't seem likely by 808140 · · Score: 1

      How right you are! And after thinking about it, I concur that Zorn's Lemma is a necessary prerequisite to making this particular example work. But here's a shot at it, assuming Zorn's:

      Let \Omega_n be a function mapping C^{n+1} to C. As a corollary of the Axiom of Choice, R is well ordered; and because R and R^2 have the same cardinality, there exists a bijection between them. Because R^2 is trivially isomorphic to C, we can show easily that if R is well ordered, C is well ordered. Therefore, of the n roots (counting multiplicity) of the polynomial with coefficients a\in C^{n+1}, we can pick one which is the largest, or the smallest. Let \Omega_n(a) be that root.

      Then \Omega_n(a) is an analytical solution to the polynomial a_{n+1}x^n + a_n x^{n-1} \ldots a_1. Therefore, by repeated application of polynomial long division and \Omega_n, we can obtain all n roots (including multiplicity) to the polynomial designated by a.

      Yes, it requires the Axiom of Choice (so much stuff does) and yes, it uses the rather peculiar well-ordered reals corollary of the axiom of choice, which most mathematicians consider the wierdest of them all, but, if you accept the axiom of choice, this angle should work (although I'm open to flaws in my logic being pointed out to me, of course).

      But then, this means that computing Omega_n requires first coming up with a well ordering on the reals. Good luck *grin*

    8. Re:This doesn't seem likely by Skwinx · · Score: 1

      Is AC really needed? Put any total ordering on the complex plane, for example by ordering everything first by magnitude and then by going around circles counterclockwise starting from the positive real axis. This isn't a well-ordering on C of course but it induces one on every finite subset of C. So for some p(x) over C we can just take its smallest root with respect to this ordering. I don't believe we need AC to guarantee a choice function in this circumstance.

      Compare the usual proof that well-ordering implies AC: let X_alpha be a collection of sets indexed by I and let X be the union over I of the X_alpha. Put a well-ordering on X and then define a function f : I --> X by taking f(alpha) to be the minimal element of X_alpha as a subset of X. This constructs a choice function. But we don't actually use exactly that X is well-ordered, just that there is an ordering under which every subset we're interested in has a minimal element.

    9. Re:This doesn't seem likely by DrEasy · · Score: 1

      Thanks for the explanation! So am I correct in saying that if we extended the definition of "analytical" to include integrals for solving polynomial equations (that's contrived too, since I don't know if integrals would be of any use), it wouldn't do much good, because we can't solve integrals analytically either (even using other integrals)?

      --
      "In our tactical decisions, we are operating contrary to our strategic interest."
    10. Re:This doesn't seem likely by miskatonic+alumnus · · Score: 1

      Aha! That sounds right to me.

    11. Re:This doesn't seem likely by 808140 · · Score: 1

      You know, when I was first thinking of how to respond to miskatonic alumnus, I was thinking of a very similar ordering to the one you described; but then I kept thinking that it couldn't be that simple. Of course the key here is that we aren't dealing with a polynomial of infinite order, and so by the FTA we know that the number of roots is finite. So a total ordering like the one you're describing is perfect, and we can throw out much of the BS in my original post. Thank goodness, the AC makes me nervous :) Not to mention that your definition of Omega is thus constructive, and so we can actually compute it.

      Math rules :)

    12. Re:This doesn't seem likely by 808140 · · Score: 1

      Well, if you care about the number that comes out at the end (most mathematicians don't, hehe), technically at some point you have to compute everything numerically. Even basic stuff like addition needs to be done numerically, right? It just so happens that we can do some addition in our heads. Computers think of addition as being an analytical composition of binary operations, likewise with subtraction; multiplication is repeated addition, division definable using a long division algorithm; exponentiation repeated multiplication, etc, etc. We use numerical approximations for virtually everything we need to compute. Most numbers cannot be conveniently expressed as finite decimals.

      So, for example, there are known solutions to high order polynomial functions that are analytical in terms of elleptic fuctions, which are typically defined in terms of integrals. Those integrals cannot themselves be solved using addition and subtraction, but they can be approximated -- and that isn't so bad, because you have to approximate everything that isn't a non-repeating decimal when you use computers. And you can rigorously bound how much error you have, too, so you even know how accurate it is.

      I mean, when you type 1/3 into your calculator, you get an approximation. Think about that.

      As for solving integrals analytically using other integrals, you could use substitution or integration by parts or whatever identities you want from calculus to turn the integral you're trying to solve into another, equivalent integral; and if that's all you want, you can say that you've "solved" the integral in terms of another integral, but is that useful? Sometimes it is, because numerical methods on some kinds of integrals converge very fast, whereas others don't. If your goal is a number, a value, or whatever, then this could have genuine use.

      We mathematicians generally dislike numbers because they make everything messy. That's for engineers and physicists. We'd rather keep things clean and exact, and as abstract as possible :)

    13. Re:This doesn't seem likely by DrEasy · · Score: 1
      First of all thanks for your clear and detail replies!
      We mathematicians generally dislike numbers because they make everything messy. That's for engineers and physicists. We'd rather keep things clean and exact, and as abstract as possible :)
      I guess I'm thinking like a programmer then, trying to express a complex problem in terms of a combination of simpler ones. What I really had in mind was whether for some particular poly equations it makes sense to do a transformation into an equivalent expression that uses integrals (or whatever "omega" function that mathematicians are comfortable dealing with), in the hope that the new expression will be easier to simplify and ultimately to solve. Not a general solution then, but it might help in some cases? Or maybe helpful if approximation methods for that particular "omega" are more effective and efficient...
      --
      "In our tactical decisions, we are operating contrary to our strategic interest."
    14. Re:This doesn't seem likely by HorsePunchKid · · Score: 1
      Are you sure you're using the term "analytical" properly? Certainly in the field of analysis, the natural logarithm is an analytic function. That is, it is differentiable at every point in its domain.

      You define it differently, pretty much as a function with a finite number of terms using the field operations. Fair enough, and I follow what you're saying from there. But that's definitely different from what I learned from taking real anaylsis and complex analysis.

      Here's a token MathWorld definition, though I know that's not definitive. I'm well aware the definitions can change significantly from area to area in mathematics.

      Anyway, regardless of semantics, great explanations, and thanks for sharing!

      --
      Steven N. Severinghaus
    15. Re:This doesn't seem likely by miskatonic+alumnus · · Score: 1

      Why does AC make you nervous? It's used in most major areas of mathematics. "Countable union of countable sets is countable" needs choice. "Every vector space has a basis" needs choice. AC is coool.

    16. Re:This doesn't seem likely by 808140 · · Score: 1

      The Axiom of Choice makes me nervous for the same reason that Euclid wrote most of the Elements without using his fifth postulate. If you use the Axiom of Choice, you are necessarily restricting yourself to an AC-universe. Not that there's anything wrong with that (just as there's nothing wrong with the Euclidean plane) but a proof which does not need AC is more general because it applies to both worlds. You know this, of course :)

      Maybe saying "AC makes me nervous" is the wrong way to say what I mean. Perhaps a better way to say it would be, I'd rather not use AC if I can avoid it.

    17. Re:This doesn't seem likely by miskatonic+alumnus · · Score: 1

      For a while many mathematicians were cautious in their use of AC, and tried to always mention where it was necessarily used in a proof. Nowadays, it's not such a big deal, because the mathematical universe without AC is not very interesting. Measure theory, for example, becomes almost trivial.

      If you are interested, and haven't read it already, Moore's "Zermelo's Axiom of Choice" is an excellent introduction to the history and use of this wonderful little addition to ZF.

      My own personal favorite use of choice is the Banach-Tarski paradox. That result, and its proof, are beautiful!!

  57. Implications by nnnneedles · · Score: 1

    IANAP (I am not a pencil), but could anyone tell me what practical implications this could have?

    --
    Will code a sig generator for food
    1. Re:Implications by (H)elix1 · · Score: 1

      IANAP (I am not a pencil), but could anyone tell me what practical implications this could have?

      If he found an easy way to factor large polynomials, this has the potential to make a mess of the public/private key encryption. Slashdotted, so have not actually looked at the site yet.

  58. Reminder... by Famatra · · Score: 1

    This reminds me of a story that Slashdot posted about someone having a new perspective on time which turned out to be a hoax. I bet if you find the story you can get some karma :o).

    1. Re:Reminder... by capnjack41 · · Score: 1

      You're not talking about the TimeCube, are you?

    2. Re:Reminder... by Creepy+Crawler · · Score: 1

      I guesss the "story" being on April 1 dosnt give any clues?

      --
  59. Re: Downloadable PDF is in English by Alwin+Henseler · · Score: 1
    (for those who can't read articles in Dutch)
    Well, more exactly: in math-speak, which I understand somewhat, but not quite enough to fully understand the details of the method.

    Anyway, I understand the problem, and that this is a general solution to it, and advances an age-old mathematical problem where no significant progress was made in over a century. So: cool! And kudoz to its inventor!

  60. Re:run away! by novakyu · · Score: 1

    > Niederländisch ist nicht deutsch!

    hoc uidetur Germanus mihi.

    Isn't it? I just started learning German, but I haven't seen any other language that calls German deutsch.

    PS. What about Pennsylvania Dutch? Ist Pennsylvania Dutch deutsch?

  61. Dear friend by clowe · · Score: 0

    I hare received your name from diplomatic friend as someone of discretion who is good. I have a formula to determine the roots of any polynomial equation that was given to me by Nigerian General Chinue Achebe. Unfortunately, I cannot get this out of country in its current form. Can you give me digits of your checking account, to which I can apply this formula. In exchange, I will give you all digits to the right of the decimal point.

  62. No closed formula by MoobY · · Score: 4, Insightful

    Note that the student's result is not a closed formula, and is thus not in conflict with Abel's proof. The system uses convergence (and thus, reuires an infinite number of operations) to find the correct roots.

    --
    --- Sigmentation Fault - Comments Dumped
    1. Re:No closed formula by Anonymous Coward · · Score: 0

      but for enginering purposes say a few hundred iterations should be fine

    2. Re:No closed formula by Skavookie · · Score: 1

      Even if it were a closed formula it would not neccesarily conflict with Abel's proof. Abel proved that the roots of the general polynomial cannot be found using only a finite number of additions, subtractions, multiplications, divisions, and radicals. See Abel's impossibility theorem.

    3. Re:No closed formula by Skavookie · · Score: 1

      For engineering purposes there are already plenty of ways to find the roots of general polynomials.

    4. Re:No closed formula by sustik · · Score: 1

      Using Galois theory you can decide whether an actual polynomial can be solved using radicals (the 4 basic operations and root finding). There are actual polynomials of which roots cannot be expressed from the coefficients. I do not remember one exactly, but you can construct one as follows: take any 5th degree polynomial with 3 (different) real and 2 complex roots. The root permutations (Galois group equivalent) becomes S_5 the symmetric group of order 5 (take a 5-cycle and conjugation) which is an unsolvable group.

  63. Non slashdotted link to the pdf: by Anonymous Coward · · Score: 0

    http://hal.ccsd.cnrs.fr/docs/00/00/32/74/PDF/The-r oots-of-any-polynomial-equation.pdf

  64. Re:run away! by Anonymous Coward · · Score: 0

    Niederländisch ist nicht deutsch!

    At least get the German right! That would be:

    Niederländisch ist nicht Deutsch!

  65. Real Men use HP's by Anonymous Coward · · Score: 0

    the HP 49G Plus beats any TI. With a 200MHz ARM cpu and compactflash memory card slot, theres no stopping it!

    1. Re:Real Men use HP's by shobadobs · · Score: 1

      Except that you are completely wrong in your information. The G+ has an ARM cpu of aboout 75 MHz, and it has an SD card slot, not compactflash.

      Also, its speed is effectively much less than 75 MHz, because the ARM processor just emulates a Saturn processor.

      Also, the 49G+ has an utterly poor-quality keyboard -- many keypresses just aren't detected, and some people are having keys break on their hinges entirely.

    2. Re:Real Men use HP's by Anonymous Coward · · Score: 0

      no, the CPU really is 200MHz, you can run a program to change the speed. and any new programs aren't emulatated. Even the OS is only partially emulated, the inner loops are not.

      As for the keypresses, HP will replace any with broken keys. The newest calculators have great keyboards.

      You are correct about the memory card slot though.

    3. Re:Real Men use HP's by shobadobs · · Score: 1

      If you read comp.sys.hp48, you'll keep hearing people complaining about the new keyboards breaking as well. Also, new programs still suffer from the emulation layer, unless they're written explicitly for the ARM -- and most software is written in SysRPL.

      The calc does not get sold with the capability of 200 MHz already built in -- which makes that useless for most users.

    4. Re:Real Men use HP's by Anonymous Coward · · Score: 0

      "you'll keep hearing people complaining about the new keyboards breaking as well."

      Ever notice its the same few people? These imbeciles don't know how to treat hardware properly. The 49g+ is no weaker then the TI-89 for instance

      "and most software is written in SysRPL."

      Most old software maybe. New software is being written in C, as sysRPL is a stupid and wrthless language that the world is better off without.

      "The calc does not get sold with the capability of 200 MHz already built in -- which makes that useless for most users"

      Those people wouldn't care what speed the calc is running at anyway. If you don't know how to download a program, you are a moron.

  66. I for one... by Anonymous Coward · · Score: 0

    Welcome our mathematically inclined Dutch overlords.

  67. what about complex solutions? by Anonymous Coward · · Score: 0

    the author seems to ignore complex solutions. in this case why not just use Newton's method from first semester calculus? that does the same thing....

  68. Does it matter? by airjrdn · · Score: 1

    I'm sure this has it's benefits, and the student definitely deserves a good pat on the back, but will it make Doom 3 run any faster? ;-)

  69. Re:run away! by Anonymous Coward · · Score: 0

    Nederlands, like English is Engels, and German is Duits in Dutch.

  70. I did something similar by Ann+Coulter · · Score: 4, Informative

    I used hypergeometric functions to solve the equation

    a x^b + c x^d + e x^f = 0

    where the exponents are integers and the coefficients can be complex. I tried to generalize it for complex exponents but I quit after a while. Google should provide some preliminary information on using hypergeometric functions to solve the quintic

    a x^5 + b x^c + e = 0

    where c is less than 5 and greater than zero.

    This is an analytic solution to the general trinomial that I found empirically (without proof). If one wants to solve to solve the quartnomial then two dimensional structures, quintnomials need 3 dimensional structures. This was computationally taxing on me and my computer so I didn't even consider the quartnomial equations.

    By the way, I have implemented a Jenkins-Traub algorithm not so long ago that gives numerical approximations to general polynomial roots. It is fast and well known.

  71. Re:Man does the well-known by Gr8Apes · · Score: 3, Interesting

    Using series to approximate the solution of differntial equations is taught in class. Heck, go a little further in mathematics and you'll conjure up polynomials functions as the solution to a set of partial differential equations, known as the Galerkin Method

    So in what way is the above news? (Hint, take a look at the link and what's stated there.)

    --
    The cesspool just got a check and balance.
  72. Go Dutchers! by Anne_Nonymous · · Score: 2, Funny

    er...

    Dutches...
    Dutchians...
    Hollandistas...
    Holla ndics...
    Netherlandites...
    Netherisks...

    Hmmmm...??? In any case, good job, people!

  73. Re:run away! by mithras+the+prophet · · Score: 4, Funny

    (Mods, parent was mistaken, but not a troll).

    My favorite word in the 503 message was geblokkeerd. That's what I'm going to use instead of "slashdotted" from now on -- "Oh no! The site is geblokkeerd!"

    --
    four nine eighteen twenty-7 thirty-nine forty-7 fiftyeight sixty-nine seventy-9 eighty-8 one-hundred-and-nine one-twenty
  74. Re:Damn, 11 Years too late by Anonymous Coward · · Score: 0

    Please read the end of the paper. "We still need s1, which is why we set s=a0 and a01". s1 must be true for this to work. So this is not a general solution.

  75. funny++ by Anonymous Coward · · Score: 0

    Shit, I wish I hadn't used all my mod points.

  76. Re: Exact solutions are useful by Alwin+Henseler · · Score: 3, Insightful
    Some may think a good approximation of a calculation problem is "good enough". Too many variables or numbers? Just throw a more powerful calculator at the problem.

    Not so. Exact solutions like the ones provided by mathematical formulas are still useful for a number of reasons:

    • Using an exact formula can provide a shortcut, that enormously reduces the amount of calculation you have to do. It also allows to do some calculations by hand.
    • More important: an exact solution provides insight in the relation between its variables. That's very important from an educational point of view. And by substituting in other formulas, this can also advance the state of the art in other areas of science. A numerical solution, or a progression towards certain values might help you believe there is a certain relation between variables. An exact solution can help you prove such a relation. That is very significant for any sort of theoretical science.
  77. Here's a math prof's take on the paper by 192939495969798999 · · Score: 4, Insightful

    From a seasoned math professor's reading of it: "It looks like a mess to me.
    I don't know what his point is. He says its a "method of solving the roots"
    of a polynomial. Well, we already have very fine methods for doing that,
    interval Newton methods for instance. Using circular disk arithmetic in the
    complex plane we can find all the complex roots as well.
    There is no need whatever to make things more complicated such as going to
    differential equations. That is unneccessary. Root finding is an algebraic
    problem."

    --
    stuff |
    1. Re:Here's a math prof's take on the paper by Carnildo · · Score: 1

      The problem with Newton's method is that it isn't certain to converge. Other methods converge, but are slower than Newton's. If this method is both fast and certain to converge, it's an improvement.

      --
      "They redundantly repeated themselves over and over again incessantly without end ad infinitum" -- ibid.
    2. Re:Here's a math prof's take on the paper by chruska · · Score: 1
      This problem has already been solved. In 2001 John Hubbard, Dierk Schleicher, and Scott Sutherland published a paper called "How to find all roots of complex polynomials by Newton's method" in Inventiones Mathematicae (one of the most prestigious math journals). I think the title pretty much speaks for itself.

      Here's a short selection from a review of the paper by Peter Haïssinsky, which illuminates why this problem is difficult, and why (in my opinion) a naive approach to a solution is not likely to work.

      "The paper under review answers the long-standing question of finding all the roots of any complex polynomial in one variable (by using Newton's method). This problem is difficult because, e.g., C. McMullen has proved that there are no generally convergent purely iterative algorithms for solving polynomials of degree 4 or more. Even in degree 3, there is a set of positive measure of polynomials for which a set of positive measure of initial guesses will not converge to any root with Newton's method.

      "The authors answer this question by providing, for each degree d, a universal set S_d of initial guesses such that, for any polynomial of degree d (suitably normalized) and any of its roots, at least one point in S_d converges to it. This set has approximately 1.11d log_2 (d) points which are equally distributed on a small fraction of log d circles. In the case of real polynomials, this number can be brought down to 1.30 d. In the final section of the paper, the authors construct S_d explicitly."

    3. Re:Here's a math prof's take on the paper by buzzdecafe · · Score: 1

      He went on to say:

      "I could have done that myself. I just didn't want to."

  78. See Mathematica Poster: "Solving the Quintic" by high+na · · Score: 4, Informative

    In this poster, they discuss this topic precisely, including Abel's theorem. One of the readers was correct: although Abel proved impossibility of solution for polynomials higher than degree 5 IN TERMS OF ROOTS AND OTHER ALGEBRAIC ENTITIES, there is nothing ruling out a solution in terms of, say, hypergeometrics. This is precisely what they do, and there's a nice development of this using power series. So, although I didn't get to read the PDF, it seems from the posts here that this is what the student did. Thus, no big deal. That said, I salute the student for figuring this out on his own, and he shouldn't be discouraged by discovering something that is not new.

  79. Bullshit by siskbc · · Score: 1
    thats not german, its dutch! and dutch is not even like german - i mean no(t many) germans understand dutch out of the box...

    Actually German and Dutch (and english) are very similar. I'm an American who learned German, and I once started teachin myself Dutch but stopped because it seemed too easy. Still, I could read half the damned article.

    --

    -Looking for a job as a materials chemist or multivariat

  80. hype by sangdrax · · Score: 1

    The whole thing is starting to be a media hype here in Holland. The news sites (including big dutch ones like NOS and AD) all seem to copy the information from the same sources, but nowhere is his proof actually verified.

    Some sites falsely claim he can find the roots of /any mathematical function/, some sites falsely claim /formulas have been found for polynomials up to grade 5/. They clearly do not know what they're talking about.

    He himself is quoted as saying to have discovered the new quadratic formula but which is applicable to all degrees. This is quite strange when considering Abel's theory, and the fact he uses 2 pages to describe his solution, one of them filled with a visual description of the matrices he uses.

    It seems like noone bothered to call a university to verify it; also, the mathematical world knows nothing about this proof and it has been on the schools site for weeks (apparently). It all seems totally overhyped.

  81. Re:run away! by jejones · · Score: 1

    As many have said, it's Dutch, not German.

    I don't know why it would scare the crap out of you; aside from Frisian, Dutch is as close a language to English as you'll find. (We'll see, I guess, how long it takes for an Englishman or Englishwoman to say that I should've written "Aside from American and Frisian...")

    That said, Dutch wasn't subject to the major changes that English underwent largely thanks to those Normans back in 1066. Dutch still has a word order that German speakers would find more natural than English speakers ("I have my Uncle Jan a pen bought," "You must him teach that he that must do"), and Dutch is sprinkled with the sort of compound words that German has, e.g. the Dutch tourism organization called the VVV (Verenigingen voor Vreemdelingenverkeer). I've read that the Dutch refer to them humorously as staathuiswoorden, literally "city hall words."

  82. Better than that by MarkusQ · · Score: 3, Insightful

    You can solve them if you're prepared to write the roots in terms of elliptic functions, IIRC
    You can do "better" than that. If you're prepared to write the roots in terms of logical functions, you can "solve" anything.

    Want the roots of f(x) = 0?

    They are

    {All x : f(x)=0}
    There are even computer implementations of this for limited cases (called "generate and test" algorithms). But I wouldn't advocate running big headlines claiming
    Cranky /. poster solves everything!
    -- MarkusQ
    1. Re:Better than that by Zenzilla · · Score: 1

      Also: the set of all roots to polynomials with rational coefficents is a countable set. This means there can exist a turning machine to calculate the digits of each possible root. When a specific polynomial is given, say #5123, we can just use the turing machines that generate the roots for that polynomial(#5123). For example turing machine #23404538 might generate the 5th root of polynomial #5123.

      What does this show?

      There exists an algorithm to find the roots of all polynomials with rational coefficients.

      I have trouble believing this algorithm works for all polynomials with real coefficients. I say this because now the number of possible polynomials is an uncountable set so we run out of turing machines before we run out of roots(Cantor's Diagonalization) to be calculated. Hence no algorithm to calculate those root(s).

  83. Re:run away! by dkruythoff · · Score: 1

    I'm a Dutch citizen and I find that offensive!!

  84. Re:Heh. by Anonymous Coward · · Score: 0

    Well, it gets a lot harder when you have multivariate polynomials.

  85. Re:run away! by cyberfoxz · · Score: 1

    Dear Anonymoes coward, this has nothing to do with the fact that both languages are somewhat similar for non Germanic speakers. The real issue is that there has been long tradition of Dutch not liking German(language/people etc.) Some say it has to do with WW II, but I think it is just a cultural phenomenon, just like Greeks/Turks and Irish/Scots, maybe even USA/Canada. Pleas try to think before jumping to conclusions (hmz, seems I've heard that being said before on /.)

    --
    --- In a world without fences, who needs Gates.
  86. Re:Heh. by Anonymous Coward · · Score: 1, Funny

    Albert? Is that you?

  87. Can we get a grip here by The+Subliminal+Kid · · Score: 2, Insightful

    Some Dutch kid is very bright and has found a rapidly converging power series for finding roots. It has been done before but may be this one is slightly more or less cool that the others.

    What this does have any sodding effect on is Abel's Impossibility Theorem which is a good thing because it would screw up lots of other things that take Abel as axiomatic.

    All credit to the kid I certainly never produced anything a tenth that far about my school grade and this is the slack news season.

  88. Reading the math... by Planetes · · Score: 1

    I just knew my engineering education would come in someday. Just never expected it to be on slashdot. :-)

    --
    Planetes
    "One World, One Web, One Program" - Microsoft Promo Ad
    "Ein Volk, Ein Reich, Ein Fuhrer" - Adolf Hitl
  89. What is even more surprising... by al701 · · Score: 0, Redundant

    ...is that the schools website wasn't ./ed in the first 5 mins of this posting.

  90. HP calculators have had this for years by Anonymous Coward · · Score: 0

    Just press the "solve" key. No problem.

    1. Re:HP calculators have had this for years by lightdarkness · · Score: 1

      The calculators go through a much more complicated process.

  91. ... guaranteed solution formulae here by 192939495969798999 · · Score: 3, Informative

    more quotes from the professor: "The "range" software of Oliver Aberth (that I have on our computer) can find
    all the roots, real and complex, of any polynomial to whatever accuracy you
    specify. Of course the more you ask for, the longer it may take, but it's
    pretty fast for ten places for polynomials of degree say ten or so.
    His book "Precise Numerical Methods Using C++" describes the methods used in
    his range software."

    Those are guaranteed solutions, too, not just "i think it's pretty close, but there's no way to prove it."

    They also have guaranteed solvers for nonlinear (and/or partial) DE's... this kid is about 50 years too late.

    --
    stuff |
    1. Re:... guaranteed solution formulae here by coult · · Score: 1

      I was really trying to believe what you were saying until I got to this:

      They also have guaranteed solvers for nonlinear (and/or partial) DE's...

      Are you joking? That is like saying "they have guaranteed solvers for any equation of any kind at all." What is meant exactly by a "gauranteed" solver?

      Does that mean that the hundreds/thousands of papers published each year on numerical methods for differential equations are all a waste of time? Heck, all those authors could have saved themselves a lot of time and just picked up a copy of Aberth's book!

      --

      All is Number -Pythagoras.

  92. Portugesespanish? by Anonymous Coward · · Score: 0

    Sounds Portugreek to me.

    (with apologies to Waterworld)

    1. Re:Portugesespanish? by Anonymous Coward · · Score: 0

      (with apologies to Waterworld)

      Someone should be apologizing for Waterworld, not to it.

  93. Duh by JustNiz · · Score: 2, Insightful

    >> Dutch student found a formula to determine the roots of any polynomial equation. Does this conflict with Abel's proof that such a formula cannot exist?

    If something exists, the fact that it can exist is irrefutable.

  94. "Tijdelijk niet beschikbaar!" by Anonymous Coward · · Score: 0

    is apparently Dutch for "Slashdotted like a cheap Amsterdam ho!"

  95. slashdot walkabout by phyruxus · · Score: 5, Funny

    How to solve a polynomial
    1) put poly in standard form and take the first n-1 derivatives.
    2) put the derivatives in terms of x(s) (for 1..n-1), or remember why you dropped calculus and goto step 9.
    3) Use the derivatives to write a differential equation with coefficients m1..mn, or remember why you dropped differential equations and goto step 9.
    4) Use the original equation to reduce the differential equation to order n, and note the use of "then" instead of "than" in the mit write-up. (sorry, mit).
    5) Substitute a formula for x(s), multiply resulting eq by it's denominator, getting another diffEq. Whee! ask a Grad student.
    6) Now substitute a power series representation. All 's' should be zero. (mutter: Aha! I knew it) Solve b_sub_i for 1..n-2 (Grad student).
    7) Substitute another power series to get an equation. (The grad students are gone, ask your hallmates, one of 'em has to be a math major.)
    8) Let b_sub_n-1 equal the determinant of a funky, unexplained matrix (here, have an aspirin).
    9) Everyone else in the class is out drinking by now, so don't worry about the next matrix, it's even funkier. Write a note on your hand to memorize it this weekend. Go drinking with peers.
    10) Wake up at 3pm tomorrow, and try to remember what the hell all those squiggles meant.
    11) Change your minor from math to polisci. Don't worry about taking Calc 1-3, DiffEq, or linear algebra. Note: many girls do not care about the roots of arbitrary polynomials, so no worries there. 8^)

    --
    "A witty saying proves nothing." ~Voltaire
    "d'Oh!" ~Homer
    1. Re:slashdot walkabout by BengalsUF · · Score: 2, Funny

      12) Profit!!!

    2. Re:slashdot walkabout by Anonymous Coward · · Score: 2, Funny

      Hrm...

      You are quick to point out the "then" vs. "than" in the writeup, yet you use "it's" when clearly "its" is called for. "It's" is never used for possession- rather, 'it's' used to mean it is (as I have so cleverly demonstrated).

    3. Re:slashdot walkabout by GuardianAngus · · Score: 1

      WTF!!!

      Where is the 'Profit' step.... This isn't even worth patenting!

    4. Re:slashdot walkabout by ryanvm · · Score: 1

      You lost me at 1).

    5. Re:slashdot walkabout by okmnji · · Score: 1

      You only need Calc 1-3, DiffEq, and linear algebra for a math minor?! Where I come from, those are freshmen level courses required for all math and engineering, and most science, disciplines. The minor involves classes where you seem to be asking grad students. But who really cares? I agree with the drinking bits, personally.

    6. Re:slashdot walkabout by Anonymous Coward · · Score: 0

      At my college, differential equations was the difference between whether or not you got a math minor if you were in computer science.

      we had more math than anyone who wasn't an actual math student.

      We didn't need Diff -- the engineering students did. The engineering students didn't need discrete math or numerical analysis -- only comp scis and math students need those. =)

    7. Re:slashdot walkabout by emmons · · Score: 1

      Where I went to school, engineers needed both. Or at least the EE students did. My university didn't have minors. I got bored and switched to Econ.

      --
      Do you even know anything about perl? -- AC Replying to Tom Christiansen post.
  96. Re:run away! by Anonymous Coward · · Score: 0

    I guess their resentment is to be expected. Let me say that I for one think the Dutch are cool (not just because of their anti-software patents stance) and even though we do tease eachother all the time, I hope they don't really think too bad of us.

  97. Re:run away! by dasmegabyte · · Score: 1

    The site had Dutch text, isn't that wierd?

    --
    Hey freaks: now you're ju
  98. Dutch? Could be worse. Could be Scots by xyote · · Score: 1

    as in here (via the
    Register.

  99. FYI by Anonymous Coward · · Score: 0

    FYI, I can't read Dutch.

  100. An applied mathematician's take by coult · · Score: 2, Insightful

    From what I can tell, it appears to be a method for transforming a polynomial into a differential equation some of whose solutions are roots of the polynomial. From that point I suppose one could use numerical methods for ODE's to find those solutions.

    People here have been commenting that Newton's method works just fine for finding roots of polynomials. But, convergence can be quite slow, especially for unidentified multiple roots though, and for highly clustered roots you can run into conditioning problems.

    The paper makes no mention of actual numerical algorithms (in particular no discussion of convergence rates or guarantees for solving the ODE numerically) so it is hard to say whether the result is actually useful or just a bunch of manipulation of symbols on paper.

    --

    All is Number -Pythagoras.

  101. Re:run away! by Anonymous Coward · · Score: 0

    Het is geen Duits. Het is Nederlands.

    By the time you figured this out, you'll understand....

    daim

  102. Re:run away! by Tharsis · · Score: 1

    > I've read that the Dutch refer to them humorously as staathuiswoorden, literally "city hall words."

    We do? Sheesh, somebody could have told us...

  103. Re:Dutch? Could be worse. Could be Scots by mikael · · Score: 1

    They're not going to outsource our jobs without having to learn our culture first!

    --
    Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
  104. Re:/.'ed, try this Coraled URL using another sourc by Anonymous Coward · · Score: 0

    did not work

  105. Translation by curtvdh · · Score: 3, Informative

    Disclaimer: it has been years since I've spoken Dutch. What follows hsould be taken with a fairly large grain of salt...

    Fontys student develops important mathematical discovery

    While most students languished on the beaches this Summer, Fontys student Geert-Jan Uytdewilligen discovered the solution to one of the oldest mathematical problems. He proved an inportant step in - wait for it - the classification of the zero-points of polynomials of any order.

    This problem was already known to the ancient Egyptians. During the Renaissance, a clearer understaning of (the problem) existed, and one 19th century scientist published (a paper) on his findings that stated the problem could not be solved. But Geert-Jan Uytdewilligen, a fourth-year student at Fontys High-school of Applied Science finally shed light on the complex problem. He discovered a formula for the classification of the zero-points of any order. Mathematical proofs have thus far not come from the sixth grade.

    Difficult Puzzles

    Ever since his youth, Geert-Jan Uytdewilligen was obsessed with the solution of difficult puzzles. 'I always feel at home in abstract thought', he says, 'In elementary school, I was very good at arithmetic, and therefore in my future studies, I stuck to mathematics. At one particular point in (my) mathemetics lesson, (we) handled the parabola. From that moment, I became interested in the pure algebraic problems that flowed from that. In particular, the higher grade comparison of the zero-points intruiged me, since mathematicians had been searching for a solution to the problem for ages. This was a challenge for me, to solve the problem which is purely theoretical. I had a slight practical advantage, because one can usually fill in the numbers(?) with a computer. The problem is then solved in this manner.'

    Polynomials

    Geert-jan designed mathematical formulae that were previously regarded as not-undestandable by the layperson. Perhaps you might recognize this formula: a[n]*x^n+a[n-1]*x^(n-1)+..+a1*x+a0=0. 'This is the general form of a regular polynomial', he says. Regular polynomials are a combination of increasing powers and multiplication. If you solve for x in this formula, then you get the zero-points of the polynomial. Polynomial solutions up to the sixth order are already known. I found a formula to find the zero-points of a polynomial of any order!'

    Publication

    Geert-Jan's discovery first saw light of day in the magazine Science Guide, and generated a lot of publicity. This was the reward of two years of hard work. Geert-Jan: 'You don't expect such a vague starting-point to result in such a hit. This is strange, considering the amount of technical jargon, which make the theory hard to follow. But at the same time, the pieces of the puzzle began to come together. Yes, I had the Eureka-moment! But I remained a freely sober person, and held myself together. I didn't allow my studies to suffer because of my hobby.'

  106. whats the fuss? by Vlion · · Score: 1

    Its a series approximation to a function solution.
    We did this in second semester calculus in a different form.
    It might be interesting to compare with, speed-wise,
    but its nothing amazingly new.

    --
    /b
    |f(x)dx = F(b) - F(a)
    /a
  107. Exact solutions are useful, but aren't possible by fizbin · · Score: 1

    Except that in the case covered here, there are no exact solutions that can be found. There cannot exist a general analytical root-finding formula for arbitrary-degree polynomials, because some of them have solutions that really aren't algebraic numbers.

    The only thing we can have is better ways of determining numeric approximations, and that's what we've got here. It seems a Dutch student invented a better mousetrap, and the world is beating a path. However, I fail to see what all the hype (well, aside from on slashdot) is about: we could get numeric approximations before, too.

    1. Re:Exact solutions are useful, but aren't possible by Anonymous Coward · · Score: 0

      Of course they're really algebraic numbers. The definition of an algebraic is that it's the root of a polynomial with integer coefficients. They just can't always be expressed in terms of a finite number of elementary operations and root extractions.

  108. Uh, Latex? by Anonymous Coward · · Score: 0

    The thing is barely readable. I would like to think that anyone with half a clue would be using Latex to present such information.

  109. Re:run away! by sporty · · Score: 1

    Tnx. Looked like it though. I see i opend up a can of worms by mixing up the two. :)

    --

    -
    ping -f 255.255.255.255 # if only

  110. In this case, more like by Anonymous Coward · · Score: 1, Funny

    12) Profess!!!

  111. I wonder if anyone will get this... by Anonymous Coward · · Score: 5, Funny
    It's a shame the paper doesn't say why this is better than using Sturm sequences

    Less Drang.

    1. Re:I wonder if anyone will get this... by Anonymous Coward · · Score: 0

      For those that wanted an explanation...

      http://www.bartleby.com/65/st/Sturmund.html

    2. Re:I wonder if anyone will get this... by timmfin · · Score: 1

      You (and I) have read too much Harry Potter.

    3. Re:I wonder if anyone will get this... by almightyjustin · · Score: 1

      Harry Potter didn't make it up any more than the poster did.

      --

      Omnes arx vestrum sunt adiuncta nobis.

  112. Re:run away! by Anonymous Coward · · Score: 0

    Dutch is not harsh at all, it's the most floppy, softened germanic language there is out there.

    Well, besides English, anyway.

  113. It's been done before by Anonymous Coward · · Score: 0

    Good work from a college student, but it's been done over 140 years ago:
    http://library.wolfram.com/examples/quintic/main.h tml#diffeq

  114. Looks flawed by hanwen · · Score: 4, Informative

    Looks flawed to me. He performs a sensitivity analysis in the constant of the polynomial (which he calls "s"). It remains unclear why. After a convoluted sequence of operations, he derives a power series for x as function of s , and proves convergence by requiring |s| smaller than 1.

    Finally, he puts back a_0 into s, but conveniently forgets the case that a_0 is bigger than 1.

    Also, it is not clear whether this is in the complex plane or not. For example, for finding real roots of real polynomials, you could use Sturm Sequences. There's even sample code in graphics Gems IV (IIRC).

    In any case, the student was studying at the "hogeschool" which roughly translates to "higher professional education", a school which doesn't teach mathematics, and whose level which significantly lower than Dutch the MSc., BSc. or engineering degree.

    Han-Wen

    (yes, I am a mathematician)

    --

    Han-Wen Nienhuys -- LilyPond

    1. Re:Looks flawed by mwillems · · Score: 1
      In any case, the student was studying at the "hogeschool" which roughly translates to "higher professional education"

      A "Hogeschool" is a university-level school, certainly at BSc/MSc level. "HTS" is the technical-type scho that you are referring to.

      --

      ---
      BDOS ERR ON A:>
    2. Re:Looks flawed by Anonymous Coward · · Score: 2, Informative

      I believe he chose the variable s due to the Laplace Transform, which I am sure you must have learned in a 1st/2nd year Calc course.....

    3. Re:Looks flawed by Anonymous Coward · · Score: 4, Informative
      Finally, he puts back a_0 into s, but conveniently forgets the case that a_0 is bigger than 1.

      Except he doesn't forget this. He tells you to divide the polynomial by a constant to make it so. Since you're a "mathematician" let me help you visualize this difficult step:

      18x^6 - 12x^3 + 3 = 0 ... divide by 6
      3x^6 - 2x^3 + 1/2 = 0

      Gee, a_0 is less than 1 now and the roots are the same. Huh, I wonder how that happened? In actuallity he tells you to divide by a larger number such that all of the coefficients are fractions, but you get the picture.

    4. Re:Looks flawed by ninja0 · · Score: 4, Insightful

      Nope, grandparent was right. You can't just divide and expect convergence to suddenly occur. I believe the leading coefficient is assumed to be 1 for the result he's using. IAA math major.

      --
      --If the world didn't suck, we'd all fall off.
    5. Re:Looks flawed by oGMo · · Score: 2, Insightful
      (yes, I am a mathematician)
      Well then,
      After a convoluted sequence of operations,
      Sounds like precise mathematical terminology and understanding of the operations.
      In any case, the student was studying at the "hogeschool" which roughly translates to "higher professional education", a school which doesn't teach mathematics, and whose level which significantly lower than Dutch the MSc., BSc. or engineering degree.
      Typical academic arrogance. Letters after your name do not make your more correct. From what I've seen, the more letters you have, the less "new stuff" you're going to come up with. You may be right in this case---but show where the mathematical errors are, don't point at credentials.
      --

      Don't think of it as a flame---it's more like an argument that does 3d6 fire damage

    6. Re:Looks flawed by hanwen · · Score: 1
      A "Hogeschool" is a university-level school, certainly at BSc/MSc level. "HTS" is the technical-type scho that you are referring to.



      I think you are out of date by approximately 20 years. There used to be Technical High Schools (THs) which were renamed to Technical Universities some 15-20 years ago. Hogeschool has since become the general term for the practically oriented sub-university level educations.

      FWIW, I studied mathematics at the Technical University Eindhoven, and my dad also taught there when it was still called "Hogeschool"

      --

      Han-Wen Nienhuys -- LilyPond

    7. Re:Looks flawed by hanwen · · Score: 2, Interesting
      You may be right in this case---but show where the mathematical errors are, don't point at credentials.

      The problem is that it is not "mathematics," in the sense that he doesn't write a logical sequence of formally specified lemmas, proofs or conclusions. It is not clear what the author is doing, so it is also not possible to pinpoint exactly where the errors are.

      --

      Han-Wen Nienhuys -- LilyPond

    8. Re:Looks flawed by Anonymous Coward · · Score: 3, Informative

      Read the paper. There is no such assumption that a_n=1. (Why else have a_n in the numerator of equation 5 if it's always 1?) He is quite explict about dividing by "(more than) the maximum of the absolute values of the coefficients". Dividing by any non-zero constant (even complex) does not change the roots of the polynomial at all.

      Assuming his formula are correct for the expansion coefficients, the series is guaranteed to converge once you perform the recommended normalization. The grandparent is wrong, and so are you! But good use of the slashdot technique of commenting without reading the paper, I guess that's how you get your "Interesting" score.

    9. Re:Looks flawed by eluusive · · Score: 2, Informative

      If you read the proof all the way through, you'll see that a_0 is required to be less than 1.

    10. Re:Looks flawed by Sage+Gaspar · · Score: 2, Insightful

      This kid is in what I'm guessing is the equivalent of a really good technical high school, so he deserves praise for just being at the level of messing around with this kind of stuff, let alone attempting to publish a paper. I'm sure some of his paper is lost in translation, but, commenting on the paper itself, it would never get accepted into a reputable journal for publication.

      First, he never gives any clear indication whatsoever of what he intends to prove that his method will do. What does it mean to provide a method for "solving the roots" of a general polynomial equation (determine one root, determine all roots, determine all real roots, etc)? Is the polynomial expressed over an arbitrary field, the real numbers, or the complex numbers? What is a "powerseries of s"? The power series of a function is defined as an infinite polynomial that converges over a certain interval to the value of the original function. S, as far as I can tell, is a constant, so thus a power series of s would be s itself.

      It might seem like nitpicking, but it's ambiguities like these that make it nearly impossible to read this paper and determine its correctness.

      I could pore through it, guessing at the meaning of unorthodox terminology and then proving everything that he hasn't proven to the level of mathematical rigor. But that's his job, and the job of his mentors/advisors and the referee at whatever journal he tries to submit this to.

      Furthermore, issuing a press release hyping this as the solution to a long-sought-after open problem is irresponsible. The only problem this has the potential to solve is finding a faster algorithm for computing roots (real, complex, I'm not sure, he didn't say), but the paper does not address whether this is, in fact, any better at all than current root-finding methods. Even if so, it certainly wouldn't make mathematical waves except in some very select circles, were it not that he was in high school.

      So, I apologize if this sounds harsh. I certainly couldn't have done this in high school, and it has the potential to shave some overhead off finding the roots of certain polynomials, which would be a nice little result. But I felt it necessary to explain why this paper isn't yet real mathematics.

    11. Re:Looks flawed by mwillems · · Score: 1

      Then I stand corrected. As a Dutch Canadian I owuld not be surprised.

      --

      ---
      BDOS ERR ON A:>
    12. Re:Looks flawed by Anonymous Coward · · Score: 0

      I guess Hogeschool or sub-university would be the equivalent of a "community college" here in the west/US. The community college gives training for the specific business' in the local area. I.E. computer operator. Usually the equivalent of an associates degree (2 year degree). One tends to use them to beef up on skills that one is weak in before they transfer to a bigger University. Sort of like pre-University.

      At first I thought Hogeschool meant something like it's a bunch of "Whooee!" when pronouncing "Hoge" in dutch as an english speaking person! The "W" and "g" as "W" and silent "g". :)

    13. Re:Looks flawed by hanwen · · Score: 1
      Dividing by any non-zero constant (even complex) does not change the roots of the polynomial at all.

      exactly: dividing does not change the problem at all, which also means that dividing the polynomial should also not change the convergence of the solution series. Anyway, I have Kreyszig (1993) sitting next to me here, and I can't figure out how page 789 is related to his condition (10).

      --

      Han-Wen Nienhuys -- LilyPond

    14. Re:Looks flawed by dajak · · Score: 1
      Typical academic arrogance. Letters after your name do not make your more correct. From what I've seen, the more letters you have, the less "new stuff" you're going to come up with. You may be right in this case---but show where the mathematical errors are, don't point at credentials.

      Part of the news value for me, as an employee of an establishment that used to be called 'university' before the EU decided to harmonize education systems and upgraded these kinds of schools to universities, is that this paper was produced by a student of a hogeschool. Academic arrogance is what makes a story 'hogeschool student produces proof of something' newsworthy in the Netherlands regardless of how relevant the something is.

  115. Enthusiasm without truth! by Thinkit4 · · Score: 2, Funny

    Argh, they need to make a way to skip all "funny" comments in any science article. So much enthusiasm for math and physics--so little truth.

    --
    -I am an elective eunuch.
    1. Re:Enthusiasm without truth! by Anonymous Coward · · Score: 0

      Er, just mod funny to -5 in the prefrences?

  116. I can't believe nobody's noticed this... by sixpaw · · Score: 3, Interesting
    ...as others pointed out, this is simply the method of power series, and it's even a pretty clumsy way of getting at that power series (why generate a differential equation when you can plug power series coefficients into the original equation itself?)

    What I'm surprised at, though, is that nobody's pointed out the most obvious problems with this scheme:
    1. Your polynomial has (up to) n roots; this approach converges, maybe, to one of them. Which one do you get, and how do you get the others?
    2. For that matter, some chunk of those n roots may be complex; but all the maths in his article are real. How do you solve, say, x^6+1 = 0?
    The change in radius of convergence at the end of his post is a little dicey too, at least as I'm reading it, but I could be misreading. Still, I'm frankly stunned. Worthy of a press release? If I'd turned this in as a school assignment it wouldn't even have been worth an A!
    1. Re:I can't believe nobody's noticed this... by soroka · · Score: 2, Informative
      ...why generate a differential equation when you can plug power series coefficients into the original equation itself?...

      When you substitute power series into an algebraic equation of degree higher then 2, you get a system of true nonlinear equations for the coefficients of the series.
      Example:
      (b0 + b1 * s +... )^3 + a(b0 + ...) + s = 0
      gives
      b0^3 + a b0 = 0
      3 b0*b1^2 + a * b1 + 1 = 0
      ...
      In contrast, the paper arrives at a system of linear equations.
  117. Obviously you're not in the correct character set by Anonymous Coward · · Score: 0

    Press alt-253 (ASCII), NOT alt-0253 (Unicode).

  118. Professional by thrill12 · · Score: 2, Interesting

    Not a mathematician here, but just a fellow dutchman who likes to add that even though the student in question isn't studying at a university, that doesn't simply mean he couldn't have come up with a nice idea.
    Besides, at the "Hogeschool" there is teaching of mathematics, just not in the same way as at an university: It is much more "practical" - ie. without going through all the 'proving-stuff' - and the level is generally lower than at a university. But the technical studies still provide an adequate level of mathematics, as necessary for any serious engineering work.

    --
    Slashdot: stuff for news, nerds that matter, matter for news, stuff that nerd
  119. Mod up! by Anonymous Coward · · Score: 0

    Whatever moderator that failed to rate parent +5 funny is seriously lacking in elementary literary knowledge.

    1. Re:Mod up! by Hatta · · Score: 1

      Please explain.

      --
      Give me Classic Slashdot or give me death!
    2. Re:Mod up! by Anonymous Coward · · Score: 1, Informative

      Look up the "Sturm and Drang period" :)

    3. Re:Mod up! by scapermoya · · Score: 2, Informative

      Sturm and Drang was a pre-romantic movement in Europe, somewhere around the 1780's i believe. Some of the famous Classical composers dabbled in it, I think Beethoven has a Sturm and Drang piece. It died quickly and gave rise to the Classical (then romantic) movement.
      The name of the period comes from a play by Friedrich Klinger, I think it means "Storm and Urge"

      Funny, we discussed this today in academic decathlon.

      --
      Beware the Jubjub bird, and shun the frumious Bandersnatch.
    4. Re:Mod up! by bandersnatch · · Score: 1
  120. Re:run away! by Anonymous Coward · · Score: 0

    Isn't it? I just started learning German, but I haven't seen any other language that calls German deutsch.

    But the Dutch don't call their language Dutch. We call it Nederlands. So it seems more like the English-speaking world used a particularly strange naming scheme:

    German for Deutch
    Dutch for Nederlands

    The reason might be that some dialects of the Dutch language were originally called Nederduits or Platt and this language was more or less spoken in the northern parts of Germany as well. Later Germany moved to High/Standard German (Hochdeutsch), while the Dutch formalized a less Germanic variant. However, you cannot say that the languages were ever the same. If you look at the oldest line of Dutch, written in 1066, it reminds me most of Dutch with Scandinavian and a little bit of English influence:

    Hebban olla vogala nestas hagunnan, hinase hic anda thu?
    (Have all birds started on their nests, except me and you?)

    PS. What about Pennsylvania Dutch? Ist Pennsylvania Dutch deutsch?

    Yes, they are originally of German-speaking descent. Another example of strange naming, since the logical name would be Pennsylvania Germans.

  121. damn, you're right. by phyruxus · · Score: 3, Funny
    Note to self: preview pedantic posts.

    Shitsurei shimashita *cuts off finger*

    --
    "A witty saying proves nothing." ~Voltaire
    "d'Oh!" ~Homer
  122. NUMERIC method by khrtt · · Score: 2, Interesting

    It's a nice NUMERIC method. There are other numeric methods that do the same exact thing. This one is nice. It may be better to implement, and/or easier to use than other common numeric root finders. This method is, therefore, not only valid, but perhaps very useful science. The next time I need to write a root finder, I will definitely give this a close look. BUT THIS HAS NOTHING TO DO WITH ABEL'S THEOREM!!!

    Abel's theorem proves that no exact root finder is possible. It has nothing to do with numeric root finders, except for making them a little more interesting for practical applications.

    What I mean is, even if exact root algorithm were possible, numeric root finders would still be useful. For many problems where an exact solution does exist, a numeric solution is more useful. An good example would be Gaussian elimination (for solving systems of linear equations).

    Gaussian elimination gives an exact solution. If you try to use it in practice, with coefficients given as floating numbers, you realize that for many matrices the rounding errors kill the precision of the result. A common cure for this is to run a few iterations of a numeric approximation method on the output of the Gaussian elimination, which improves the precision.

    Now, back to root finders. An exact solution is not possible for polynomials of degree higher than 5. It is possible for polynomials of degrees 1, 2, 3, and 4. However, the formulas for degree 4 get rather long. So long a numeric method would quite possibly be more accurate. It would not write the roots out in radicals, but the floating point representation (that's what you want anyways, right?) would be more precise.

    The point of this essay - when you need numeric results, numeric methods are often more useful than precise formulas, even where precise formulas exist. If Abel's theorem were wrong, you'd probably still use numeric root finders in most practical cases.

  123. Got root? by KenSeymour · · Score: 1

    I just couldn't resist.

    --
    "We can't solve problems by using the same kind of thinking we used when we created them." -- Albert Einstein
  124. Re:run away! by Anonymous Coward · · Score: 0

    It's all about the World Cup finale in 1974. The Dutch still hold a grudge for that one.

  125. Re:run away! by tigertiger · · Score: 1
    Maybe the poster should be forgiven the error.

    Confusingly enough, "Dutch" is actually derived from the word "Deutsch" that Germans use to refer to their language.

    For your entertainment: In German this could be
    (trying to keep as close to the original as possible)

    Diese Site ... ist zur Zeit nicht verschickbar wegen zu viel Datenverkehrs.
    [Deze site ... is tijdelijk niet beschikbaar vanwege te veel data-verkeer.]

  126. +5, plz by Trepidity · · Score: 1

    Only because there is no +6.

  127. I can't believe I'm about to say this, but... by whyde · · Score: 2, Funny
    If you don't restrict your base, you open yourself up to the attack that I just used with the omega function...

    If you don't restrict your base, all your base are belong to us. Take off every Omega function!! For great roots!

    I'm so ashamed of myself.

  128. Edsger W. Dijkstra by Anonymous Coward · · Score: 0
  129. Antony van Leeuwenhoek by Anonymous Coward · · Score: 0
  130. Re:Rule of equations in school (7337?) by WuphonsReach · · Score: 1

    Why 7337?

    I could understand 1337...

    --
    Wolde you bothe eate your cake, and have your cake?
  131. MOD PARENT UP by ninja0 · · Score: 1

    IAA math major. Parent is right--this paper makes a mistake trying to prove convergence. Heck, it's so hard to read and unrigorous I'm not sure if it works at all past the second equation.

    --
    --If the world didn't suck, we'd all fall off.
  132. Rough translation by LiquidCoooled · · Score: 0, Offtopic

    blah blah blah ....... pie ........

    blah blah blah .... got root ....

    yadda bladda radda..... polyphonic ringtones.... ....tumm tee tumm.

    Good job Im going on holiday and dont have to think about anything complicated ;)

    --
    liqbase :: faster than paper
  133. A Really Simple Way to Do It by strook · · Score: 1

    It's not very hard at all to figure out a numerical method for finding zeros of a polynomial. Here's a simple way to do it.

    1. Let f'(x) be the derivative of f(x).
    2. Recursively find all the zeros of f' and put them in a sorted list.
    3. Add a really big negative number and a really big positive number to the list.
    4. For each two consecutive numbers in the list, call them a and b. If f(a) and f(b) are either both positive or both negative, there's no zero between a and b. Otherwise there is exactly one zero between a and b.
    5. If there's a zero between a and b, we can numerically approximate it by repeating:
    * pick c = (a+b)/2
    * check f(c), pick d from {a,b} so that f(c) and f(d) are opposite signs
    * recurse with a,b = c,d

    I waved my hands a little bit but not too much. I'll leave calculation of how big the "really big" numbers have to be and how well we need to approximate the zeros of the derivative as an exercise for the reader. ;-)

    --

    "TV is great! Every New Year's I make a resolution to watch more TV." - Ann Coulter

  134. Some high order polynomials can be solved exactly. by Caractacus+Potts · · Score: 1

    Just to clarify, when people say that polynomials of order n>4 can't be solved exactly with radicals, they mean that they can't generally be solved. Some of them can be solved exactly. For instance, see if you can solve the following 6th order polynomial. (x-1)^6 = 0.

  135. For one.. by Creepy+Crawler · · Score: 1

    There's a realy good method I use to approximate Square roots.

    1: You choose said number to "squareroot-ize".
    (227)
    2: You list List closest natural square above and below said number.
    (15, 16)
    3: Now, treat this as a fraction where the deniminator is the distance away from X^2 and (X+1)^2
    ( 16^2 - 15^2 = 31)
    4: The numerator is the difference between the chosen number to square root to the lower natural square.
    (227-225 = 2)
    5: Now craft and solve said fraction.
    (2/31 = roughly .064 )
    6: Add on to the fraction the lower natural square to obtain an accurate square root using fractions. Higher numbers are, of course, more accurate.
    ( 15.064- fraction 15.066-true square root)

    --
  136. Re:Rule of equations in school (7337?) by alcmena · · Score: 1

    Yeah, that's what I meant. Ugh, I hate it when I bungle a joke.

  137. Does it work for imaginary or complex roots? by Anonymous Coward · · Score: 1, Informative

    Although I am not a mathematician, only a humble theoretical physicist, I think I understand the method and I believe that the author has come up with a clever algorithm for solving polynomial equations. Although the mathemaitcs involved is elementary (real analysis only) the note is a bit hard to follow because the presentation is a little awkward and chaotic even for a physicist (mathematicians have much higher expectations regarding the style of a scientific paper). This is a minor point, the author is probably very young and has plenty of time to master the art of scientific writing.

    An important question is whether the method can be extended for computing imaginary or complex roots (other algorithms can do this without major problems).

    Regarding the solution of algebraic equations of order higher than 4 by formulas, I remember vaguely that about 30 years ago I read that analytic formulas exist which involve transcendental functions (probably elliptic functions, I dont remember exactly). Of course, such formulas do not invalidate Abels' result which refers to formulas invoIving elementary functions such as square or cubic roots, etc. In addition, formulas involving special functions are hard to use, it is much easier to apply numerical methods.

  138. Screw MATLAB, go octave by jearbear · · Score: 1

    They may not be able to afford MATLAB, but instead, they can use octave!
    http://www.octave.org/

  139. personaly by Anonymous Coward · · Score: 0

    I can say "reading dutch is the easy part"

  140. Mathematical Elucidation by logicnazi · · Score: 4, Informative

    Alright, whoever wrote the article seems very confused about mathematics and abel's theorem in particular. I'm not actually an algebraist myself but I am in mathematical logician so I can comment a bit about impossibility results.

    Abel's theorem merely says you can not solve the general quintic (5th degree) or higher in terms of radicals. That is entierly in terms of multiplication, addition, and taking nth roots. If we don't put that restriction about radicals the solution is trivial. Let x be such that P(x)=0 is one obvious solution.

    Going through this again the write up is *entierly wrong*. It is completly possible to give an exact solution for the general polynomial (I just did in the paragraph above). Furthermore this distinction between exact and numerical solutions which is made so much of by our high school and college teachers is really illusionary. Writing a solution in terms of sin(3) isn't an exact value, we just have a good algorithm to approximate sin. Really what we mean when we talk about exact solutions is solvable in elementary functions, which is nothing but a certain commonly used set of functions for which we have good approximations. Unfortunatly, we still insist on students 'solving' differntial equations rather than just finding some quickly converging numerical solution even though at a deep level these are not differnt.

    Now since abel's theorem there has been considerable research on other ways to solve polynomial equations. For instance one big result was that a certain degree of polynomials could be solved in a terms of continous two place function. Possibly this result in question is another result like this one but I imagine it is much less significant. For one I'm not entierly convinced he is correct, nor novel. (Don't make the mistake of assuming if he is right he has given a continous solution of any polynomial..it isn't clear his solution is continous in the coefficents).

    --

    If you liked this thought maybe you would find my blog nice too:

    1. Re:Mathematical Elucidation by Anonymous Coward · · Score: 0

      It is completly possible to give an exact solution for the general polynomial (I just did in the paragraph above).

      When you use the word solution you imply a question, and whether or not your statement is correct depends on the precise statement of this question.

      Furthermore this distinction between exact and numerical solutions which is made so much of by our high school and college teachers is really illusionary.

      The distinction between exact and numerical solutions are not illusionary as long as you provide definitions of what they are.

      Writing a solution in terms of sin(3) isn't an exact value...

      If you define solution as "a real number written as an exact finite decimal expansion", then you are correct. But this is not necessarily the case.

      I'm not sure if you actually have a legitimate point with your numerical/exact argument, but it really doesn't appear that you do to me. Maybe I'm missing something?
    2. Re:Mathematical Elucidation by Sage+Gaspar · · Score: 1

      Errm... not exactly.

      The writeup is a little unclear, but to the layperson (and, I wager, most mathematicians), a solution to an n-th degree polynomial is either an explicit function in the coefficients of the polynomial that returns a root as its value, or a sequence that converges to such a root. "Let x be such that P(x) = 0" is no stronger than the fact that a root exists, and doesn't tell you anything about what such a root will be (is it real, complex, rational, integral, algebraic, prime, etc, etc).

      Secondly, the distinction between sin(x) and a good algorithm approximating sin(x) is vast. In practicality, I'll give you that it makes sense to equip our engineers and scientists with numerical methods, and there's a rich field of mathematics devoted entirely to it. In fact, almost every decent engineering or science program requires an upper level course in differential equations and numerical methods that should cover a lot of this ground.

      However, proving things with some semblance of rigor would take a whole lot more work with a numerical approximation, and I'm guessing some theorems would prove impossible without having the actual value of a function, rather than being in some epsilon neighborhood of the value.

      Let's put it this way: we have a rigorous definition for exactly what it means to be the sine of an angle (several congruent definitions, in fact), and it doesn't make sense to spread the nonsense that a numerical approximation for sin(3) is exactly the same thing as sin(3). However, it does make sense to spread the word that when it comes down to crunching numbers, numerical approximations are the name of the game.

    3. Re:Mathematical Elucidation by logicnazi · · Score: 1

      Sure, if you define exact solutions and numerical solutions in a rigorous manner you are correct. What I am really saying is that the way most HS/intro college classes are taught these terms are not defined in such a manner. At best they are defined in a misleading manner which doesn't really reflect the intuitive notion to these words.

      Yes, you can defined an 'exact' solution to be one written in terms of elementary functions of integers. This is what is commonly assumed in HS/intro-college course. Unfortunatly, the fact that we are merely stipulating elementary functions as 'exact' isn't told to the students. Instead they are incalcated with the notion that solutions not written in terms of elementary functions are somehow less valid.

      As an example let us consider a course in differential equations. Students are told that sin(x) is a solution of x''+x=0 which is perfectly fine. However it is implied, if not explicitly said, that a quickly converging power series solution of the same problem is only an approximation. The implication being that it is somehow a less worthy solution while as a matter of fact sin(x) is nothing but shorthand for a particular power series (depending on how you define it of course).

      In this age where engineers will be using computers to solve their problems it is inappropriate to waste time writing solutions in terms of particular historically important functions. It should be conveyed to the students that any algorithm guaranteed to converge to the solution is valid and algorithms which converge faster are better regardless of whether they can be written out in terms of familiar symbols.

      --

      If you liked this thought maybe you would find my blog nice too:

    4. Re:Mathematical Elucidation by logicnazi · · Score: 1

      Read my above reply for more details.

      The short answer is that sin(x) is really just a nice abbreviation for a certain power series (or other type of series if you wish). Any series guaranteed to converge to a particular value is a valid solution, those which converge faster or have nicer properties are better solutions.

      Regardless of the technical details I am just sickened by seeing students bludgened into horrible manipulations to solve a diff eq in terms of elementary functions (sin, cos etc..) when an algorithmic (or power series) solution which converges quickly is readily apparent.

      --

      If you liked this thought maybe you would find my blog nice too:

  141. Re:run away! by Anonymous Coward · · Score: 0

    the dutch call the german language "duits".
    So thats more close to deutsch then german.

    We dutch and deutschers are much alike .
    ( start the puns )

  142. Oh, yeah .... by gstoddart · · Score: 1
    I think being captain of the math team is far and away a better thing than being the captain of the freakin football team.


    'Cause we all know the captain of the maths teams is more likely to get blowjobs from cheerleaders than the captain of the football team is. =)

    In terms of actually doing something that is useable in society, sure the maths geek has a lot going for him. However, this whole 'revenge of the nerds' thing whereby we stand up and reclaim the proud nature of our geekiness doesn't actually convince anyone but us.

    And, rest assured, that if being the math champion starts to get you play with the honeys, you will see the number of people trying to be the math champion go up.

    Cheers

    --
    Lost at C:>. Found at C.
  143. Re:run away! by Anonymous Coward · · Score: 0

    because of too much data-verkeer.

    That's "data-traffic."

  144. Complex roots? by Anonymous Coward · · Score: 0

    I don't have any desire to decipher this paper, which is atrociously written even by mathematical standards. However, from a cursory observation of the formulae, I fail to see how his formula will give complex roots for a polynomial that happens to have real coeffs. Nothing he does in the paper -- take derivatives/determinants/divide/sum infinite series -- is going to turn real coeffs into complex roots.

    So I think this is pure BS.

    1. Re:Complex roots? by Anonymous Coward · · Score: 0

      Well, near the bottom of page 1 he says "b0 is a root of an n-1 degree polynomial ..." So b0 can be complex to start with (he doesn't really explain how to find that root either). I suppose you could apply his "technique" iteratively until you got down to 2nd order, then use the quadratic equation to find 2 of the b0.

      Of course when I tried to follow the paper with a simple 2nd order example, b0 was the root of a n (2) degree polynomial, but maybe I made a mistake, it is hard to follow his instructions.

      Damn slashdot and its minimum character per line requirements. Here's my attempt for the starting part:

      a2X^2 + a1X + S = 0 ... (1)

      Take 1 derivatives of (1) wrt s:

      2a2XX' + a1X' + 1 = 0

      X' = - 1/(2a2X + a1)

      Make up a whole new equation:

      m1X' + m2X + M3 = 0

      -m1/(2a2X + a1) + m2X + m3 = 0 ... (2)

      -m1 + 2m2a2X^2 + m2a1X + 2m3a2X + a1m3 = 0

      "Using (1)..., we simplify ... [by] setting [(simplified (2) equal to (1) (0 = 0)]"

      2m2a2X^2 + (m2a1 + 2a2m3)X + a1m3 - m1 = a2X^2 + a1X + S

      Solve for m1, m2, m3:

      m2 = 1/2

      m3 = a1/(4a2)

      m1 = (a1^2/(4a2) - S

      thus

      (a1^2/(4a2) - S)X' + X/2 + a1/(4a2) = 0

      substituting (3) gives:

      (a1^2/(4a2) - S)Y' + Y/2 = 0 ... (4)

      Which at least is a nice simple first order differential equation. At that point I'm sort of lost 'cause the power series is X(S) = b0 - a2/(2a1) which leads to a 2nd order equation for b0.

      From there, I'm lost.

  145. Come on, he's Dutch... by Anonymous Coward · · Score: 0

    He's gotta be smoking something!

  146. Re:run away! by jejones · · Score: 1

    My source on that is a Mario Pei book I read back in junior high, whose title I can't recall...so I will definitely defer to a more knowledgeable source!

  147. Massachusetts by Exousia · · Score: 1

    Massachusetts --- And that's suppose to be a credit to him?

    --

    --Slashdot: News for Turds. Stuff that Splatters.
  148. what? by Trepidity · · Score: 1

    I don't see Harry Potter even mentioned here.

  149. I think... by Anonymous Coward · · Score: 0

    ... geklobbeerd might be a more adequate translation of "slashdotted".

  150. That's IBM PC extended ASCII by Ayanami+Rei · · Score: 1

    That's just for the standard VGA character set, and it applies nowhere else (bizarre, eh?).

    Actually, ISO-8859-1 (ASCII with extended Latin) puts a 2 superscripted at 0xB2, and a 3 superscripted at 0xB3. 0xB0 is degree, 0xB4 is "prime", 0xB9 is a one superscripted (?), and 0xB0 is a 0 superscripted.

    So there!

    --
    THIS THING CAN TURN ON A DIME, MACROSSZERO STYLE ALSO FUCK BETA, ~NYORON
  151. I stand corrected :) by Carbon+Unit+549 · · Score: 1

    That's my southern accent in print! Oh well, at least my math is pretty in print.

    --

    nohup rm -rf ~/. >& zen &

  152. Re:Rule of equations in school (7337?) by WuphonsReach · · Score: 1

    Darn, I was hoping it was some obscure math joke that I could learn about.

    --
    Wolde you bothe eate your cake, and have your cake?
  153. The Roots of polynominal. by Anonymous Coward · · Score: 0

    Jesus. The first and second assumpton:
    Set the sum of the diritives to zero. Nice.
    Doenst work for all polynomials.

    Next in equ (3) Set n*a n = 0. Gee whiz. DIvision by Zero.

    What happens when you make a boat out of a strainer. It sinks from all the holes.

    There is so much wrong with this guys paper, Id start by giving him an F, and then make him patch all the freaking holes, cover all the cases of his assumptions, and it will make for a VERY complex problem, much harder then:

    http://mathworld.wolfram.com/PolynomialRoots.htm l

    Check it out!
    Killmo!

  154. Re:ERROR!! CRASH!! by Anonymous Coward · · Score: 0
    The main theorem of the Algebra: "A N-th order polynomial equation always has N complex solutions".

    This student doesn't mention the complex numbers, so he can't prove the convergence to each complex solution.

    open4free © : i like the pathological formulas ;D

  155. Re:run away! by Anonymous Coward · · Score: 0

    My mother tongue is Swedish and I'm actually able to understand basic written Dutch.

    It actually has a lot in common with German and Swedish which maybe isn't so strange since they're all germanic languages. (like english)

  156. Man does the impossible ... several years later by Anonymous Coward · · Score: 0

    Please follow the links below http://www2.math.uic.edu/~jan/PHCpack/phcpack.html http://www.ee.surrey.ac.uk/Personal/D.Jefferies/co mplex98/jd/cx98jd/node3.html There is a well stablished theory to obtain solutions for algebraic and differential equations as power series of a given continuation parameter. Google continuation solution

  157. Can't contradict a proof by Performer+Guy · · Score: 2, Interesting

    Proofs cannot be contradicted that's the point. That's why it's called a proof.

  158. already known for 30 years by WilbertD · · Score: 2, Informative

    a formula to determine the roots of any polynomial equation. Does this conflict with Abel's proof that such a formula cannot exist? There are some misunderstandings here. Abel's result says it's not possible to solve polynomials of degree 5 or higher in terms of multiplication, addition and taking roots. If you allow fancier functions (like elliptic functions, which are similar as sin/arcsin), it's possible to solve polynomials of degree 5 [1]. The solution that the student posted is an exact solution (no numerical one). The series is exact (unless you take only a few terms of course). You can write down its coefficients explicitly in terms of the coefficients of the original polynomial. Two important remarks: 1) There exists several classes of functions (hypergeometric functions in several variables, and Siegal modular functions) which can be used to solve polynomials of any degree (this is known since 30 years or so). See bottom of [2]. 2) The method which the student used, is also known since 30 years. It can be found in the same link [3]. So, nothing new ... [1] http://mathworld.wolfram.com/QuinticEquation.html [2] http://library.wolfram.com/examples/quintic/main.h tml#higher [3]: http://library.wolfram.com/examples/quintic/main.h tml#diffeq

  159. it works for me by soroka · · Score: 1
    With the help of fellow /.ers I have convinced myself that the method described in the Arxiv paper actually works. Here is a review for mathematically inclined reader.

    The method can be naturally separated into two steps. The first step is given an equation

    x^n + a[n-1] * x^(n-1) + ... + s = 0
    to find a differential equation
    m[n] x(s)^[n] + m[n-1] * x(s)^[n-1] + ... + m[0] = 0
    where x^n denotes x to the power of n and x(s)^[n] denotes the n-th derivative of x(s). Such equation is not unique as we shall see, but that does not matter because the second step is to find n specific solutions to this differential equation that correspond to the n roots of the original equation.

    Consider, for example, a quadratic equation

    x^2 + a*x + s = 0
    Following the author we will find m[i] by making the coefficients at x^(i) in the equation
    -2 m[2] - m[1]*(2x + a)^2 + m[0] = 0
    with the original. However, there is no unique way of doing this. Moreover, some assignments that satisfy this condition do not lead to a good differential equation! I have chosen m[0] = 0. Then m[1] = 1/4 and m[2] = (a^2 - 4s) / 2. The latter is the discriminant and it suggests that we are on the right way.

    (a^2 - 4s)/2 x'' + x'/4 = 0
    can be easily solved by looking for a solution of the form x(s) = C(a^2 - 4s)^(alpha) + D. Where C, D and (alpha) are unknown constants. After some further tweaking we arrive to the correct solution.

    The second part of the paper is about finding a solution to an ordinary differential equation in the form of infinite series. This is more or less standard technique and it can be seen that here a solution will converge for any s. It has been noted above that the reference given in the paper is probably not applicable here. It is hard to check anyway since it is to a 500 page book.

    All in all, I have found this construction original and not trivial. There are several gaps in the original paper and it would be nice to see a presentation of this technique which does not leave to many questions behind. As an occasional maths teacher I should say that the praise is well deserved. Amature mathematics can be as demanding as professional stuff. On the other hand, one should not judge mathematics on whether it solves the Riemann hypothesis or not. Just digging out a technique from a forgotten paper from 1862 is something noteworthy. Hip-hip hooray, /.ers for lending your valuable time to such aesoteric matters.

  160. Integer roots by soroka · · Score: 1
    To follow up on the logicians post should we not mention that it was once suggested that it is reasonable to consider a solution to an equation to be an algorithm that outputs a number which satisfies the equation.

    It appears that for integer solutions no such algorithm exists. That is [*] in their celebrated work Matiyasevich, Putnam and Julia Robinson have shown that no algorithm exists which can tell given an equation whether it has an integral solution or not.

    MathWorld article on Diophantine Equations[*]

    1. Re:Integer roots by logicnazi · · Score: 1

      Well this is sorta correct.

      There is no algorithm which outputs a 1 if a given diophantine equation has a solution and a 0 otherwise. It is fairly easy to construct an algorithm that outputs a solution *if one exists* but doesn't terminate otherwise. Simply search through all possible integer combinations of the variables.

      In a more technical sense the set of diophantine equations (encoded as integers of course) with integer solutions is a complete recursively enumerable set.

      --

      If you liked this thought maybe you would find my blog nice too:

  161. Stack size? by dunng808 · · Score: 1

    On that basis, Loni Anderson should have no problem parsing my root expressions; however I find that conclusion untenable. Perhaps the operative parameter is not size, but depth. Gee, and I never got to my joke about polished sausage. Maybe next time ... but wait, I'm on /.

    --

    Gary Dunn
    Open Slate Project

  162. Best bonus question EVER by David+Gould · · Score: 1

    My favorite bonus exam question (from a CS Theory midterm for the portion of the semester that covered the Fast Fourier Transform):

    (Extra credit -- 1 pt.) Simplify:

    (x - a) (x - b) (x - c) ... (x - z)
    --
    David Gould
    main(i){putchar(340056100>>(i-1)*5&31|!!(i<6)<< 6)&&main(++i);}
    1. Re:Best bonus question EVER by protonman · · Score: 1

      0, because of (x - x) ?

      --
      The man of knowledge must be able not only to love his enemies but also to hate his friends.
    2. Re:Best bonus question EVER by David+Gould · · Score: 1


      One point of extra-credit to protonman.

      --
      David Gould
      main(i){putchar(340056100>>(i-1)*5&31|!!(i<6)<< 6)&&main(++i);}
  163. Abel's theorem clarification by cletus_bojangles · · Score: 2, Insightful
    Several posters stated Abel's (or Galois'? or Ruffini's?) theorem correctly: it says that for n = 5, 6, 7, etc. there is a polynomial involving x^n whose roots cannot be expressed in terms of the four functions (+, -, *, /) and m-th roots (m = 2, 3, 4, 5...).

    But that's not the whole story. Of course, if sin(1) is a root of your polynomial, then most people would be happy and consider that a perfectly good number that we can sink our teeth into. It is in fact possible that there exist polynomials of degree 5 whose roots cannot be expressed using buttons on your calculator (assuming your calculator is somehow infinite precision). That means using exponentiation, natural logs, arcsinh, etc. A particular example is the polynomial
    2x^5 - 10x + 5

    Well, with current math we can't prove that the roots of this polynomial have this property. But if you assume the as-yet-unproven (or as-yet-disproven, take your pick) "Schanuel's Conjecture" from number theory, you can indeed prove that this polynomial's roots are in some sense "inexpressible".

    Yeah, yeah, of course you can approximate them numerically. Any australopithecine could realize that in the time it takes to gnaw an antelope femur down to the marrow.

    (Personally speaking, I find the possibility that we can't explicitly write down the roots of a quintic polynomial -- especially such a nice one -- somewhat disturbing.)

    Reference for the claims above: Timothy Chow, What is a closed-form number?, American Mathematical Monthly, May 1999, vol. 106, pages 440-448.

  164. maybe this will make it more clear.... by novakyu · · Score: 1

    Heh.

    Sorry about the Latin at the beginning of the entry. It translates to (I think), "This seems German to me." (Inspired by a quote on a T-shirt that read, "omnia sunt Graeci mihi."; oh, and this comment refers to the previous non-English sentence, "Niederländisch ist nicht deutsch."; hmm, come to think of it, shouldn't deutsch here be capitalized, as it is a noun?)

    Maybe the rest of the entry makes sense now.

    PS.Oh, and, yes, I do know the "Dutch" in Pennsylvania Dutch is a corruption of original Pennsylvania Deutsch, a dialect of German which my German 1 instructor speaks natively.

  165. Trepidity makes the link by Anonymous Coward · · Score: 0

    Hi, o.p. here. I've never read any Harry Potter. I did read some Goethe in German classes in high school. I got the same level of enjoyment from it as reading Shakespeare, i.e, not much.

    Anyway, Max Klinger did report to Colonel Potter, so I can see how timmfin could have gotten confused (the clue is in the title).

  166. Cantor's Diagonalization by MarkusQ · · Score: 1

    I say this because now the number of possible polynomials is an uncountable set so we run out of turing machines before we run out of roots(Cantor's Diagonalization) to be calculated.
    I put Cantor's Diagonalization in the same basket as Euclid's Parallel Postulate: you can get results just as "valid" by accepting or rejecting it (but the two systems you get are not isomorphic at the fringes). The contrarian position is to assert that there is in fact an integer corresponding to every real number in the open interval 0 to 1; just "place a mirror" at the decimal point. Thus 0.5 maps to 5.0, and 0.123 maps to 321.0, and so forth. Of course, a repeating like 0.3333... maps to a "repeating integer" such as ...33333.0 (and this is where most people cry foul and get off the bus). Likewise, Pi-3 maps to an infinite integer that ends in .....95141.

    The catch is, it's very hard to come up with an a priori reason that this is unacceptable, while everything that Cantor did was kosher.

    So far as I know, the situation is much like that with non-euclidian geometries; you might not like them but they are hard to "disprove" without at some point waving your hands and hoping your audience buys it.

    -- MarkusQ

  167. No, it doesn't rebut existing mathematics by Anonymous Coward · · Score: 0

    The work of Abel/Ruffini/Galois simply states that polynomials of degree 5 or higher cannot (in the general case) be solved with radicals, radicals being root extractions.

    Results similar to the dutch mathematician are well-known. For example, you can express all roots of a degree n equation using Bessell functions.

  168. finite element approximation? by js290 · · Score: 1

    It's been a while, but it seems like he just worked out the finite element approximation...

    --
    "Tempers are wearing thin. Let's just hope some robot doesn't kill everybody." --Bender
  169. This is news? His method seems a rehash... by dido · · Score: 2, Interesting

    The method presented in the paper looks a lot like James Cockle and Robert Harley's differential resolvent, which was new in 1862. This page gives an overview of some of the known methods for solving quintic and higher degree equations. Apparently, about twenty years ago Hiroshi Umemura found a general analytical solution for a polynomial equation of arbitrarily high degree involving Siegel modular forms, which are generalizations of the elliptic modular functions Charles Hermite used in 1858 as a solution to the quintic. Note: these don't violate Abel's Impossibility Theorem as they are not solutions in radicals.

    --
    Qu'on me donne six lignes écrites de la main du plus honnête homme, j'y trouverai de quoi le faire pendre.
  170. General Solutions to Polynomial equations? by trieck2 · · Score: 2, Interesting

    Being a "young student", he certainly deserves honorable mention for his discovery. Unfortunately though, I don't think that it is new math. I think it is the well-known "Lagrange Inversion Formula" in disguise. See http://encyclopedia.thefreedictionary.com/Lagrange %20inversion%20theorem Set "z" there to s. Set "w" there to x. Set "f(w)" = - (a_n x^n + ... + a_1 x). So "w = g(z)" is then x = g(s). I believe that the "a" there (the initial estimate for "w") would be -a_{n-1} / n a_n. Give it a try.

  171. That's great... by Anonymous Coward · · Score: 0

    now if you were just an attractive woman, I'd be set.

  172. Update: Ancient maths riddle remains 'unsolvable' by Antony-Kyre · · Score: 1

    http://www.expatica.com/source/site_article.asp?su bchannel_id=19&story_id=11782 13 September 2004 AMSTERDAM -- Mathematicians have dismissed claims by Dutch student Geert-Jan Uytdewilligen that he has discovered a formula to give the solution to polynomial equations of degree five or higher. Uytdewilligen claimed last week that he had found the general formula that could be used to solve the roots of any polynomial equation. It was reported at the time that mathematicians and scientists had been searching for the equation since the time of the ancient Egyptians. But Amsterdam University professor Tom Koornwinder has dismissed the idea that the world was waiting for such a solution: "It was already proven in the 19th century that this formula cannot exist".