Question

if a projectile is fired straight upward from the ground with an intial speed of 64ft per second, then its height in feet after seconds is give by the function h(t)=-16t

Answer 1

64 ft

Explanation:

if a projectile is fired straight upward from the ground with an initial speed of 64 feet per second, then its height in feet after seconds is given by the function h(t)=-16t^2 + 64t. find the maximum height of the projectile.

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h(t)=-16t^2 + 64t

complete the square

h(t)=-16(t^2 -4t+4)+64

h(t)=-16(t-2)^2+64

This is an equation of a parabola that opens upward with vertex at (2,64)

maximum height of the projectile=64 ft (2 sec after it is fired)