hello dear friends

i want to solve an equation about adding three cosine term which are constrained:

cos(2 pi(x+y-2z))+cos(2 pi(y+z-2x))+cos(2 pi(z+x-2y))=0 

with constraint 0<x<1,x<y<1,y<z<1

can some one please guide me?

i wrote this command but it did not work:

solve({cos(2*Pi*(x+y-2*z))+cos(2*Pi*(y+z-2*x))+cos(2*Pi*(z+x-2*y)) = 0, 0 <= x, x <= 1, y <= 1, z <= 1, x < y, y < z}, [x, y, z], explicit)

How can i plot a probability function such as cos(x-y)*cos(y-z)*cos^3(x-2z)=0.6 where

x=0..5, y=0..x, z=0..y.

please guide me.

i have a probability function f(x,y,z)=x^3*y*z and constraint on its ranges x<y , y<z. how can i plot it fot f(x,y,z)=0.5