Thread: Volumes

Please help me on these 2 questions on volume. Thanks!

1. y=1/x x=1, x=2, y=0

2. y=x^2 x=[0,2], y=4, x=0

Use method of disks.

area=pi(radius squared)
let the function y=1/x be the radius

pi*integral(1/(x^2)) from 1 to 2= pi/2