I am try to solve highly non-linear equations in matlab but unable to do so i already use solve command but it shows it cannot find explicit solution and use the fmincon

But in my problem i use theta and phi as 2 variable which are between the certain range but fmincon and fminbnd gives only the final results so how could we get all the results for the solution. So please help me to find all the solutions. You cal also see the attach files for the programe

Answer 1

[Walter Roberson]

You do not indicate what the equation is.

The energz function that you have in funn does not cross zero in the real domain: it has a minimum value at (pi/2, pi/2) at which location it is exactly equal to 1. It repeats another two times within the boundary for x(2) -- that is, (pi/2, 3*pi/2) is also a minima for it.

In the complex domain, there are 8 solutions in x2 for each x1 value, not counting periodicity.