Instead of having them as two separate variables, set the problem up with each variable as part of one overall variable.
So, x -> x(1) and y -> x(2)
Then, y=myfunction(x)
[x, fval, exitflag] = fminsearch(@myfunction, [x0;y0])
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!