Question 190678
The height of a missile propelled upward at 48 feet/second is given by h (t) = -16t2 + 48t. What is the maximum height that the missile will reach?
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The easiest way to do these is to find the total flight time from takeoff to impact.  The max height is at the midpoint, 1/2 the time.
Use h(t) = 0  The height will be zero at takeoff and at impact.
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h (t) = -16t2 + 48t = 0
t = 0, t = 3
Max height is at t = 1.5 seconds
h(1.5) = -16*2.25 + 48*1.5 = 72 - 36
= 36 feet