Answer:
(t, h(t)) = (4, 9256)
Step-by-step explanation:
We assume you intend the h(t) function to be ...
h(t) = -16t^2 +128t +9000
The equation can be written in vertex form as follows:
h(t) = -16(t^2 -8t) +9000
h(t) = -16(t^2 -8t +16) +9000 -(-16)(16) . . . . add and subtract -16(16) to complete the square
h(t) = -16(t -4)^2 +9256 . . . . . vertex form of the height function
The vertex of h(t) is (4, 9256), an altitude of 9256 feet after 4 seconds.
