A) given the function f(x) = -x^2 + 8x + 9, state whether the vertex represents a maximum or
minimum point for the function. explain your answer.
b) rewrite f(x) in vertex form by completing the square.

Find the vertex using vertex formula
-b ÷ 2a  -8 ÷ -2 x = 4 for y plug in 
F(x) = -(4)² + 8(4) + 9
       = -16 + 28 +9
       = 12 + 9
       = 21
(4,21)
vertex form
y = -(x - 4)² + 21
so that means it will flip down - means flip down
so vertex represents a maximum point

Is a for each hour he works,his earnings go up by $4