Your math teacher threw your cell phone off one of the overlooks on theBlue Ridge Parkway. The equation representing the path it took to the depths below is given by h(t) = -10t^2 + 10t + 60 where h(t) represents the height, in meters, of your phone and t represents the time it is in the air, in seconds. How long does it take your phone to smash to the ground?
When it hits the ground, h = 0 ......so.....
-10t^2 + 10t + 60 = 0 multiply through by -1
10t^2 -10t - 60 = 0 divide through by 10
t^2 - t - 6 = 0 factor
(t - 3) ( t + 2) = 0
The first factor set to 0 gives us what we need
t - 3 = 0
t = 3 (seconds to hit the ground)