Answer: the pitch of the roof is 2/9
The maximum value can be determined by taking the derivative of the function.
(dh/dt) [h(t)] = h'(x) = -9.8t + 6
Set h'(x) = 0 to find the critical point
-9.8t + 6 = 0
-9.8t = -6
t = 6/9.8
Plug the time back into the function to find the height.
h(6/9.8) = -4.9(6/9.8)^2 + 6(6/9.8) + .6
= 2.4
And I don't understand your second question.
The sum of 4.35 and -5.66
You multiply 86 by 42.5 because each board is 42.5 and there are 86 boards.
