Undefined function or method 'fsolve' for input arguments of type 'function_handle'

I am trying to solve two equations with two unknowns (x(1),x(2)). The problem is when I try a generic type of solver, I get the following error:

??? Undefined function or method 'fsolve' for input arguments of type 'function_handle'.

Error in ==> solution at 3
[x,fval] = fsolve(@myfun,x0,options)

First, I write a file that computes F, the values of the equations at x.

function F = myfun(x)
F = [quad('mexicanh', 0, x(2)-x(1), 1.0e-06)-quad('mexicanh', 0, x(2)+x(1), 1.0e-06)+quad('mexicanh', 0, 2*x(2), 1.0e-06;
     quad('mexicanh', 0, 2*x(2), 1.0e-06)+quad('mexicanh', 0, 2*x(1), 1.0e-06)-2*quad('mexicanh', 0, x(2)+x(1), 1.0e-06)];

and mexicanh is a function

function y=mexicanh(z)
y=exp(-abs(z)).*(sin(abs(z))+cos(z));

then I save this function file as myfun.m and write

x0 = [-5; -5];           
options=optimset('Display','iter');   
[x,fval] = fsolve(@myfun,x0,options)

Thanks in advance

Answer 1

[Walter Roberson]

fsolve() is part of the Global Optimization Toolbox, and is not available unless you have that optional toolbox installed and licensed.