calculus
posted by Anonymous .
Find the volume when the area bounded by f(x) = xe^x, y = e, and the yaxis, is revolved around the yaxis.

xe^x = e when x = 1
using shells,
v = Int(2*pi*r*h dx)[0,.852]
where r = x
h = ey = e  xe^x
v = 2pi*Int(x(exe^x) dx)
= 2pi *Int(ex  x^2 e^x) dx
= 2pi * (e/2 x^2  e^x (x^2  2x + 2))[0,1]
= pi(4e)
= 4.03