The volume V of a right circular cone varies jointly as the square of the radius r and the height h . Tell what happens to V when r is doubled.
A)V is 4 times as large.
B)V is 3 times as large.
C)V is 2 times as large.
D)V is 9 times as large.
E)V is 6 times as large.

Question

Quizplus · Accepted Answer

Doubling the radius (r) while keeping the height (h) constant results in the volume (V) becoming 4 times as large because the volume formula for a cone is V = (1/3)πr^2h, and squaring the doubled radius (2r)^2 gives 4r^2.

The Volume V of a Right Circular Cone Varies Jointly