calculus
posted by MAM .
Use the shell method to set up and evaluate the integral that gives the volume of the solid generated by revolving the plane region about the yaxis.
y = 6x
y = 18
x = 0

V = Int(2pi*r*h dx)[0,3]
where
r = x
h = 18y
V = 2pi*Int(x*(186x) dx)[0,3]
= 2pi * Int(18x  6x^2 dx)[0,3]
= 2pi*(9x^2  2x^3)[0,3]
= 2pi*(2718)
= 18pi