Question 87764
The quadratic function that models the fireworks’ height s(x) in feet x seconds after they are launched is given by the equation s(x) = -16x^2+200x + 4.  When should the fireworks explode so that they go off at the greatest height?  What is that height? [Hint:  Find the vertex of the quadratic function s(x).] 
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Vertex occurs at x=-b/2a = -200/-32 = 6.25 seconds
Height at that time = s(6.25) = -16^(6.25)^2+200(6.25)+4 = 668.07 ft
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Cheers,
Stan H.