Question

A ball is thrown into the air. The function h(x) = -16x2 + 64x + 8 models the height, in feet above ground, of the ball after x seconds.

What was the height of the ball at the time it was thrown?
How many seconds after being thrown did the ball reach its maximum height?

Answer 1

At the time the ball was thrown, it was 8 feet above the ground.

h'(x) = -32x + 64 = 0, so x = 2

The ball reaches its maximum height after 2 seconds.