Question

Mesa stands on a balcony and throws a ball to her dog, who is at ground level. The ball’s height (in meters) x
seconds after Mesa threw it is modeled by the equation y=−x2+6x+7
.(1 point)
What is the ball’s height after 5 seconds?
meters

What is the rate of change for the interval 2 to 5 seconds?

meters per second

Answer 1

y(5) = −5^2 + 6(5) + 7 = −25 + 30 + 7 = 12 meters.

Average rate of change from x=2 to x=5 = [y(5) − y(2)] / (5 − 2).
y(2) = −4 + 12 + 7 = 15, so rate = (12 − 15) / 3 = −1 meter per second.