I have no idea where you got because I have no idea what region you are talking about!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.
It is impossible to answer this without knowing what the problem is or what you did.My Answer: 9pi.
Textbook answer: 18pi.
Where did 18 come from?