A soccer ball is kicked from the ground with an initial upward velocity of 90 feet per second. The equation h=-16t^2 + 90t gives the height h of the ball after t seconds.
What is the maximum height of the ball?
h = -16t^2 + 90t = -16(t^2 - 45/8 t) = -16((t - 45/16)^2 - (45/16)^2) = 2025/16 - 16 (t - 45/16)^2
The maximum height of the ball is 2025/16.
(The unit is missing from the question.)