Question

. Let f(x) = x2 + 2, 0 ≤ x ≤ 1. Find the volumes of the solids formed when
(d) the region enclosed by the y-axis, y = f(x) and y = 3 is rotated around the x-axis.

Answer 1

use disks

Answer 2

dV = [pi*3^2 - pi*(x^2+2)^2]*dx

Answer 3

take the integral

Answer 4

The volume is 182pi/15 ??

Answer 5

wolfram says 52pi/15

http://www.wolframalpha.com/input/?i=int_0%5E1++%5Bpi*3%5E2+-+pi*%28x%5E2%2B2%29%5E2%5D+dx

Answer 6

Would I not use the washer method:
The outer radius being y=3 and the inner radius being x^2+2
so when this is plugged in to the formula I get
38Pi/3

Answer 7

sorry yes it is 52Pi/5
Thank you!