word problem

Question

You are trying to dunk a basketball.You need to jump 2.5 ft. in the air to dunk the ball. The height that your feet are above the ground is given by the function h = -16t² + 12t. What is the maximum height that your feet will be above the ground? Will you be able to dunk the ball? 

Answer 1

The vertex is at (h,k) and h = -b/2a.

 

h = -12/-32 = 3/8

 

k = -16(3/8)² + 12(3/8)

k = -144/64 + 36/8 = -144/64 + 288/64 = 144/64 = 9/4 = 2.25

 

Nope, you will probably jam the ball into the rim.