Question

One of the parking lot lights at a hospital has a motion detector on it, and the equation
(x + 10)^2 + (y − 8)^2 = 16 describes the boundary within which motion can be sensed.

What is the greatest distance, in feet, a person could be from the parking lot light and be detected?


2 ft

4 ft

9 ft

256 ft

Answer 1

The equation is a circle with center (-10, 8) and radius sqrt(16) = 4. So the farthest a person can be and still be detected is 4 ft.