# Math Help - Rotate About the line y = 4

1. ## Rotate About the line y = 4

Find the volume of the solid generated by revolving the region bounded by the graphs of the equation about the line y = 4.

I set y = y to find the boundaries.
I found the boundaries to x = o
and x = 3.

V = pi INT from x = 0 to x = 3 of the function (x)^2 dx.

My Answer: 9pi.

Textbook answer: 18pi.

Where did 18 come from?

2. ## Re: Rotate About the line y = 4

Originally Posted by nycmath
Find the volume of the solid generated by revolving the region bounded by the graphs of the equation about the line y = 4.
What graphs? What equations?

I set y = y to find the boundaries.
I found the boundaries to x = o
and x = 3.

V = pi INT from x = 0 to x = 3 of the function (x)^2 dx.
I have no idea where you got $x^2$ because I have no idea what region you are talking about!

My Answer: 9pi.

Textbook answer: 18pi.

Where did 18 come from?
It is impossible to answer this without knowing what the problem is or what you did.