Question

The path of a projectile launched from a 16-ft-tall tower is modeled by the equation y = −16t2 + 64t +16. What is the maximum height, in feet, reached by the projectile?

Answer 1

The vertex of the parabola y = −16t^2 + 64t + 16 occurs at t = −b/(2a) = −64/(2·−16) = 2 seconds.
y(2) = −16(2)^2 + 64(2) + 16 = −64 + 128 + 16 = 80.

Maximum height = 80 ft.