1. The problem statement, all variables and given/known data Express the surface x = 2cos(theta)sin(phi) y=3sin(theta)sin(phi) z=2cos(phi) as a level surface f(x,y,z) = 144, f(x,y,z) = ? 2. Relevant equations 3. The attempt at a solution I figured they wanted the equation f(x,y,z) in x^2+y^2+z^2=144 so I though that by making the r's in the equations the same that would be the way to go.--> 24x^2+36y^2+24y^2 = 144 Where am I going wrong???