1. The problem statement, all variables and given/known data Identify surface whose equation in spherical coordinates is given p = sin(theta)*sin(fi) 3. The attempt at a solution I know that y = r*sin(theta)*sin(fi). and thus, y = rp. This yields y = (x2 + y2)0.5*(x2 + y2+z2)0.5 However, this is rather ugly. The answer is supposed to be "a sphere with radius 0.5, center (0. 0.5, 0)" however, I don't see how that results from this expression.