Reviewing for my final and got one (of many) problems I keep getting a weird answer for. The problem reads:
Use the shell method to integrate. Find the volume generated by revolving the region bounded by the graphs of and about the line .
Using the shell method I set it up as from [1,2]. However, I get a negative volume. Any help would be greatly appreciated.
Well, one possible reason you're getting negative numbers is that you should have
Sign error in there will do it every time. I think you also forgot the factor out front. Don't forget: with the shell method, you could slice up one shell, flatten it out, and you'd have a rectangular prism whose volume is quite easy to compute: The radius , like you had.
[EDIT]: Failure failed to allow my post to go first.