Question

Find the volume of the solid generated by rotating about the y axis the area in the first quadrant bounded by the following curve and lines.
y=x^2, x=0, y=2.

Answer 1

use discs or shells.

v = ∫[0,2] πr^2 dy
where r = x

or

v = ∫[0,√2] 2πrh dx
where r=x and h=y

Answer 2

What do you mean my discs and shells?