SOLUTION: THe height in feet a ball is t seconds after being throan in the air is given by H(t)=-16t^2+64t+5 A)How long did it take the ball to reach its maximum height above the ground

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Question 541823: THe height in feet a ball is t seconds after being throan in the air is given by H(t)=-16t^2+64t+5
A)How long did it take the ball to reach its maximum height above the ground
B)What was the maximum height above the ground the ball reached
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
THe height in feet a ball is t seconds after being throan in the air is given by H(t)=-16t^2+64t+5
A)How long did it take the ball to reach its maximum height above the ground
Vertex of parabola is the max:
t = -b/(2a)
t = -64/(2(-16))
t = -64/(-32)
t = 2 seconds
.
B)What was the maximum height above the ground the ball reached
plug t=2 into:
H(t)=-16t^2+64t+5
H(2)=-16(2)^2+64(2)+5
H(2)=-16(4)+128+5
H(2)=-64+128+5
H(2)= 69 feet