Question

A tennis ball is hit over a fence; the path that the ball follows can be expressed by the equation y=−1/4 x^2+8x
, where x represents the horizontal distance and y is the vertical height. In terms of the context, determine the maximum height reached by the tennis ball.(1 point)
Responses

16 feet
16 feet

64 feet
64 feet

8 feet
8 feet

32 feet

Answer 1

y = −(1/4)x^2 + 8x is a downward parabola. Its vertex is at x = −b/(2a) = −8/(2·(−1/4)) = 16.
Maximum height: y(16) = −(1/4)(16^2) + 8·16 = −64 + 128 = 64 feet.

Answer: 64 feet.