Question

The height of a small rocket fired straight upward is measured by the
function h(t) = −16t2 + 512t, where h(t) is measured in feet and t is
time in seconds.

When is the rocket at a height of 960 ft?

Answer 1

-16t^2 + 512t = 960
-16t^2 + 512t -960 = 0
-t^2 + 32t - 60 = 0
t^2 - 32t + 60 = 0
(t-2)(t-30)=0

t = 2 or 20

Answer 2

*2 or 30