y = -12 x^2 + 48 x
complete square to find vertex
-y/12 = x^2 - 4 x
-y/12 + 4 = x^2 - 4 x + 4
-y/12 + 4 = (x-2)^2
vertex, max height, when x = 2
then y/12 = 4 or y = 48 feet
y = 0 again when x = 4 seconds
The height of a soccer ball that is kicked from the ground can
be approximated by the function:
y = -12⋅x^2 + 48⋅x
where y is the height of the soccer ball in feet x seconds after it is kicked.
Find the time it takes the soccer ball to reach its maximum height: _____ seconds
What is the soccer ball’s maximum height:___ feet
Find the time it takes from the moment the soccer ball is kicked until it returns to the ground: ____ seconds
1 answer