Find the volume of the solid obtained by rotating the region bounded by the given curves about

Question:

Find the volume of the solid obtained by rotating the region bounded by the given curves about the specified axis.
(a) y = 2x, y = x2; about the x-axis
(b) x = 0, x = 9 - y2; about x = - 1
(c) x2 - y2 = a2, x = a + h (where a > 0, h > 0); about the y-axis