1. The problem statement, all variables and given/known data If the mass per unit area of a surface is given by rho = x*y, find the mass double integral over S of x*y dS if S is the part of the cylinder x^2 + z^2 = 9 which is in the first octant and contained within the cylinder x^2 + y^2 = 4. 2. Relevant equations Above. 3. The attempt at a solution I can visualize what the shape looks like, but I'm not sure how to define the bounds of integration based on the shape described.