CPM Homework Banner

Two roads intersect at right angles. Elizabeth, who is driving east, leaves the intersection traveling at a speed of mph. Two hours later, Nairi leaves the same intersection at a speed of mph heading north. How fast is the distance between the cars changing five hours after the eastbound car leaves?

Let the eastbound car be at a distance from the intersection and the northbound car at distance .
Write an equation for the distance between them.

Implicitly differentiate the distance equation with respect to time. This will create a rate equation.