1. The problem statement, all variables and given/known data Find the volume of the solid formed by rotating the region enclosed by: (e^(1x)+2)/y=0/x=0/x=.9 about the y axis 2. Relevant equations Probably disk method i would assume: V=pi*int((f(x)^2) dx from bounds a to b 3. The attempt at a solution V= pi*int(e^(1x)+2)^2) a=0 b=.9 v=pi*int(e^(2x)+4) a=0 b=.9 v=pi*(1/2e^(2x)+4x) v=pi*(1/2e^(2(.9))-(1/2e^0)+(4(.9) v=pi*(3.025)-(1/2)+3.6 v=6.125pi But my answer is not correct.
It's not your bounds that are wrong … it's your discs. Your discs should be "horizontal" discs, centred on the y-axis.