### Home > APCALC > Chapter 5 > Lesson 5.1.1 > Problem 5-9

5-9.

, for the height of the rocket at time,

*. Then determine the rocket’s maximum height and the amount of time it was in the air.*

Start with the basic equation: where

*is the initial velocity and*

*is the initial height of the rocket from the ground.*

The initial height of the rocket is

The initial velocity is

To find the maximum height, take the derivative of the function and set it equal to zero because the maximum height occurs when the velocity is zero.