1. The problem statement, all variables and given/known data The curve x=y^(2) and the line x=4 is rotated about the x axis. 2. Relevant equations pi* integral from a to b of Radius^(2) 3. The attempt at a solution pi* integral from 0 to 4 of (square root of x)^(2) dx. My teacher has this answer as 8pi but I think that that is wrong. Shouldn't it be 16 pi because you have to account for symmetry?