Question

A softball is thrown up into the air. The ball's height in feet is modeled by the equation h(t) = -16t2 + 32t + 5.
h = height
t = time in seconds
Find the maximum height of the ball.

a) 7.6 feet
b) 8.3 feet
c) 12.2 feet
d) 13.9 feet

Answer 1

max height is given by
\[t=-\frac{b}{2a}\]

Answer 2

in this case a = -16, b=32
\[-\frac{b}{2a}=1\] so maximum is when t = 1

Answer 3

but when you replace t by 1 in the equation you get none of the above answers.

Answer 4

in fact you get 21

Answer 5

I meant to add if at the begining