Question 439434
a) In how many seconds will the ball reach the maximum height? (5 pts)
b)What is the maximum height in feet that the ball reaches? (5 pts) 

s(t)=-16t^2+64t+5 
..
-16t^2+64t+5
complete the square
-16(t^2-4t+4)+5+64
-16(t-2)^2+69
coordinates of vertex(2,69)

ans:
a) The ball will reach the maximum height in 2 seconds
b) The ball will reach the maximum height of 69 ft
see graph below:

..

{{{ graph( 300, 300, -10, 10, -10, 100, -16x^2+64x+5) }}}