function g=nonlineareq(x)
% Here is an example of nonlinear system that can be solved by using 
% the Matlab command "fsolve" written in the file called "solution.m" 
% (see quasi-Newton or Levenberg-Marquardt methods).

g(1)=x(1)-4*x(1)*x(1)-x(1)*x(2);
g(2)=2*x(2)-x(2)*x(2)+3*x(1)*x(2);