Question 654892
3 sec
Let t = 3
You get -16*9+96*3 = -144+288 = 144
I did this by setting the derivative of the h with respect to t equal to zero and solving for t as follows
-16*2*t + 96 = 0 or
t = 96/32 or 3
That is the highest point in the trajectory. It turns out to be 144 feet, the solution to the problem. If the highest point was less than 144', the problem would not have an answer (couldn't reach 144'). By the way it hits the ground in 6 sec.