Path: news.mathworks.com!not-for-mail From: <HIDDEN> Newsgroups: comp.soft-sys.matlab Subject: fzero or fsolve to solve equation with symbols defined Date: Sun, 14 Nov 2010 00:34:05 +0000 (UTC) Organization: The MathWorks, Inc. Lines: 20 Message-ID: <ibnapt$s0p$1@fred.mathworks.com> Reply-To: <HIDDEN> NNTP-Posting-Host: webapp-03-blr.mathworks.com Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Trace: fred.mathworks.com 1289694845 28697 172.30.248.38 (14 Nov 2010 00:34:05 GMT) X-Complaints-To: news@mathworks.com NNTP-Posting-Date: Sun, 14 Nov 2010 00:34:05 +0000 (UTC) X-Newsreader: MATLAB Central Newsreader 2607526 Xref: news.mathworks.com comp.soft-sys.matlab:686606 Hi, In my code I define a few symbols and later on I obtain a non linear equation in one of those symbols for which I need to calculate the root. example: syms x; g = x^3 + x^2 + x + 1; % to solve for the roots of the above equation, I tried using h = fzero(g,1); It gave me the following error: If FUN is a MATLAB object, it must have an feval method. Error in ==> fsolve at 184 funfcn = lsqfcnchk(FUN,'fsolve',length(varargin),funValCheck,gradflag); How do I solve this? Thanks