A cone with height h is inscribed in a larger cone with height H so that its vertex is at the center of the base of the larger cone. Show that the inner cone has maximum volume when h=1/3H.

Printable View

- Nov 16th 2011, 09:14 AMAXQ4286Optimization: Cone inside a larger cone
A cone with height h is inscribed in a larger cone with height H so that its vertex is at the center of the base of the larger cone. Show that the inner cone has maximum volume when h=1/3H.

- Nov 16th 2011, 12:45 PMearbothRe: Optimization: Cone inside a larger cone
1. Draw a sketch!

2. Let R denote the radius of the larger cone and r the radius of the smaller cone.

Use proportions:

Solve for r.

3. The volume of the smaller cone is calculated by:

Replace r by the result of #2.

4. Use calculus to determine the maximum value of