Question 993401
A stone is thrown vertically upward from the roof of a building. The formula that describes the height h (in feet) of the stone after "t" seconds is given below.

h=-16t^2+64t+40

How many seconds after the stone is thrown would it reach for the first time 100 feet in height?
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h=-16t^2+64t+40 = 100
Solve for t.
There might be 2 solution, ascending and descending.