This what I did for the disk method (about the y-axis)
V=∫(lny)^2-(0)^2 dy...from 1 to 8
used two integration by parts
1st: u=(lny)^2, du=2lny/y dy, dv=dy, v=y
giving: v=∏[(lny)^2-∫(y)(2lny/y)]
2nd: u=lny, du= 1/y dy, dv=dy, v=y
giving: ∏[y(lny)^2-2ylny+∫y(1/y)dy
answer...
Homework Statement
Calculate the volume of the solid of revolution formed by rotating the region around the y-axis. Apply the shell method.
f(x)=e^x, x=0, y=8
Homework Equations
V=∫2∏x((f(x))-g(x))dx
The Attempt at a Solution
This is what I did: (I integrated from 0 to 8)...