Path: news.mathworks.com!not-for-mail From: <HIDDEN> Newsgroups: comp.soft-sys.matlab Subject: Re: length of the arc Date: Thu, 15 Mar 2012 01:45:17 +0000 (UTC) Organization: The MathWorks, Inc. Lines: 12 Message-ID: <jjrhjc$h9o$1@newscl01ah.mathworks.com> References: <jjquno$knf$1@newscl01ah.mathworks.com> Reply-To: <HIDDEN> NNTP-Posting-Host: www-01-blr.mathworks.com Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Trace: newscl01ah.mathworks.com 1331775917 17720 172.30.248.46 (15 Mar 2012 01:45:17 GMT) X-Complaints-To: news@mathworks.com NNTP-Posting-Date: Thu, 15 Mar 2012 01:45:17 +0000 (UTC) X-Newsreader: MATLAB Central Newsreader 1187260 Xref: news.mathworks.com comp.soft-sys.matlab:760998 "rsch tosh" wrote in message <jjquno$knf$1@newscl01ah.mathworks.com>... > y=x^3/25-3*x^2/625-2*x/15625 > I want to find the length of this equation using matlab. - - - - - - - - - The integral that gives the arc length of your curve is known in general as an "elliptic integral". As Nasser has shown, in your case it is the integral of the square root of a certain quartic polynomial. See: http://mathworld.wolfram.com/EllipticIntegral.html, and http://en.wikipedia.org/wiki/Elliptic_integral for a discussion. Elliptic integrals first became of interest in the problem of finding arc length along an ellipse, hence the name. Roger Stafford