1. The problem statement, all variables and given/known data Find the surface area of the part of the cone z = sqrt[(x^2 + y^2)] lying inside the cylinder x^2 - 2x + y^2 = 0. 2. The attempt at a solution Partial Derivative x = x/sqrt(x^2 + y^2) Partial Derivative y = y/sqrt(x^2 + y^2) so... sqrt((Partial Derivative Y) ^2 + (Partial Derivative at Y) ^ 2 + 1) = sqrt[(x^2 + y^2)/(x^2 + y^2) + 1] = sqrt so... the surface area = integral on E of sqrt r dr d(theta), where E is the region (r, theta)|(0 < r < 2, 0 < theta < pi) My books solution has the body of the integral as 5, and E as (0<r<1, 0<theta<pi) I'm pretty sure I've just made an algebraical mistake in the body, but for the limits I'm confused. I don't know how to treat a cylinder that isn't centered at the origin. I thought r was always the distance from the origin... is it really the distance from the center of the cylinder? Thanks for any help or advice you can give me.