1. The problem statement, all variables and given/known data http://imgur.com/a/emr1n ∫01 x= 4tan(pi*y/4) , Find the volume of the solid by revolving shaded region about the y-axis 2. Relevant equations tan^2=sec^2 - 1 3. The attempt at a solution I ended up with 64-16pi using u-substitution, not sure if right, want a confirmation. I only have one last attempt on mathlab so really need this to be right, would like to know how you got to whatever the answer is, or if there's a way to check the answer, that would help a lot. Wolfram hasn't been of much help :/ Thanks!