1. The problem statement, all variables and given/known data Find the volume of the solid obtained by rotating the region bounded by the given curves about the specified line. y=x2 x=y2 Rotated about y=1 2. Relevant equations Area of cross-section (in this case, a disk) = A(x) = π(outer radius)2 - π(inner radius)2 Volume = V = ∫A(x) dx 3. The attempt at a solution yellow line => y=x2 red line => x=y2 I converted x=y2 to y=√x The outer-radius is y=x2 The inner-radius is x=√x The intersection points of the two graphs is (0,0) and (1,1) So A(x) = π(x2)2 - π(√x)2 = π(x4-x) So V = ∫A(x)dx = π ∫ [ (1/5)x5 - (1/2)x2 ]dx integrated at (x=0 to x=1) = -3π/10 ... However the volume can't be negative and the correct answer is 11π/30 Any help? The book shows the same graph and same intersection points, but I am getting the wrong answer.