Hey guys, i was wondering if you can help me out with this problem...

Use the shell method to find the volume generated by rotating the region bounded by the given curves about the y-axis.

1. $\displaystyle y=x^2, $ $\displaystyle y=4, $& $\displaystyle x=0$ (Answer is:$\displaystyle 8pi$)

2. $\displaystyle y = ln(x),$ $\displaystyle y=0, $& $\displaystyle x=e $(Answer is: $\displaystyle \frac{\pi(e^2+1)}{2}$)

Thanks!