### Home > CALC > Chapter 5 > Lesson 5.1.2 > Problem 5-14

5-14.

Look at the diagram of the cylinder. The circumference of the base is equivalent to x.

*P* = 2*b* + 2*h*

25 = 2*x*+2*h*

Solve for *h*.

*V* = *π*(*r*²)(*h*). Substitute.

The volume will be at a maximum when its derivative is 0.