The height of a soccer ball that is kicked from the ground can be approximated by the function:
y = -14x2 + 70x
where y is the height of the soccer ball in feet x seconds after it is kicked.
What is the soccer ball's maximum height in feet?

87.5

Step-by-step explanation:

By completing the square,

y

=-14x^2+70x

=-14(x^2-5x)

=-14(x-5/2)^2+175/2

the max. height=175/2

i.e. 87.5

gregory's graph is incorrect because it shows 2 inches of growth for each week when it should show 0.75 inches of growth each week.