Question

The height of a soccer ball that is kicked from the ground can be approximated by the function:

y = -12x^2 + 60x

where y is the height of the soccer ball in feet in x seconds after it is kicked. Find the time, in seconds, it takes from the moment soccer is kicked until it returns to the ground​

Answer 1

5 seconds

Explanation:

Well we know that when the soccer ball is on the ground the height will be 0.

So we replace y with 0 and solve for x.

0=-12x²+60x

factor out and divide x, (this x is x=0, which is before he kicked it)

0=-12x+60

subtract 60 from both sides

-60=-12x

x=5