The question is Given a curve C whose equation is give by y=(12/(x + 3))- 4, find the region bounded by C, the line x=0, the line x=3 and the line y=8 is rotated through 360 degree about the y-axis. Calculate the exact value of the volume generated. My solution is here http://www.geocities.com/myjunkmail31/Volume.jpg However, this solution is not the answer in the textbook. The anwser in the textbook is 36pi(1+2ln2). Can someone show me where am I doing wrong?