Question

A baseball is thrown into the air with an upward velocity of 25 ft./s. It's height in feet after T seconds can be modeled by the function h(t)=-16t^2 +25t+5. how long will it take the ball to reach it's maximum height? What is the balls maximum height?

Answer 1

how about complete the square to find the vertex?
16 t^2 -25 t = -h + 5

t^2 -1.5625 t = -(1/16)h + .3125

(t - .78125)^2 = -(1/16 )h + .3125 +.61035

(t - .78125)^2 = -(1/16 )h + .923

(t - .78125)^2 = -(1/16 )(h - 14.8)

t = .781
h = 14.8

Answer 2

or
0 = 25 - 32 t
t = .781
h = 5 + 25(.781) - 16(.781)^2 = 14.8