Question

The volume of a cylinder is given by the formula v=pi r^2h, where r is the radius of the cylinder and h is the height. Which expression represents the volume of this cylinder? h=2x+7, r=x-3.

Answer 1

Substituting for r and h:-

volume = pi (x - 3)^2 *  (2x + 7)

=   pi* (2x + 7)(x^2 - 6x + 9)
= pi *  (2x^3 - 12x^2 + 18x + 7x^2 - 42x + 63)
= (2x^3 - 5x^2 - 24x + 63) pi  answer