Explanation:
knowing the physics principles and how the formulas work, the function must be
h(t) = -16t² + 96t + 256
what you did then with the second line of h(t) definition - only God knows.
anyway, to get the height of the object after x seconds, we only need to put the value of x into every place of t in the function expression and simply calculate. that is how functions work. any and every type of function.
0 seconds. t = 0
h(0) = -16×0² + 96×0 + 256 = 256ft
1 second. t = 1
h(1) = -16×1² + 96×1 + 256 = -16 + 96 + 256 = 336ft
3 seconds. t = 3
h(3) = -16×3² + 96×3 + 256 = -144 + 288 + 256 = 400ft
4 seconds. t = 4
h(4) = -16×4² + 96×4 + 256 = -256 + 384 + 256 = 384ft
6 seconds. t = 6
h(6) = -16×6² + 96×6 + 256 = -576 + 576 + 256 = 256ft
0 seconds 256 ft
1 second 336 ft
3 seconds 400 ft
4 seconds 384 ft
6 seconds 256 ft
so, after 6 seconds it is back to the same height as what it started from.