Thank you so much for your answer. Does this work? because in my case again shows (in command window):
fx(x, y) = int(exp(2*((Z_p - 1/2)^2 + (x^2 + y^2)^(1/2)/50)^(1/2)...
I think the answer shuld be only based on x,y since the equation is integral on Z_p and from 0 to 1 and -1 and 0.
Am I right? I mean why we have int and Z_p in the answer?
Thank you so much once again for your prompt reply.