A baseball player has hit a ball The height y of the ball x

A baseball player has hit a ball. The height, y, of the ball x seconds after it is hit is given by y= -16x^2 + 80x + 3.
At what time will the ball reach its maximum height? I used the quadratic formula and my answer was 2.04
What is the maximum height of the ball? I used the original formula.My answer was 232.78
When will the ball hit the ground? My answer was 4.08
Is this right??
thanks

Solution

Find the apogee, which is the vertex of the parabola:
hmax = -b/2a
= -80/(-32) = 2.5 seconds
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What is the maximum height of the ball? I used the original formula.My answer was 232.78
It\'s at time = 2.5 seconds.
y = -16*2.5^2 + 80*2.5 + 3
ymax = 103 feet
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When will the ball hit the ground? My answer was 4.08
Set y = 0
-16x^2 + 80x + 3 = 0
x = 2.5 + (sqrt(103))/4 seconds
x = ~ 5.037222891 seconds
It\'s not 5 seconds even, because the ball started up from 3\' elevation.