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.
Thanks
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.