1. The problem statement, all variables and given/known data Evaluate ∫∫ z² dS where S is the part of the surface of the sphere x² + y² + z² = a² with z>= 0 3. The attempt at a solution I get: ∫∫ (a² -x² - y²) . (1 + 4a²) a. da.dθ where dS = a. da.dθ I think I'm making a mistake somewhere, perhaps I'm getting confused with a² and r². Thanks.