Find all fixed points for the function by setting the function equal to x and solving the resulting equation for x.
-If a projectile is launched upward from a height of 160 feet at an initial velocity of 144 feet per second, then its height h after t seconds is given by the function h(t) = -16t2 + 144t + 160. After how
Many seconds does the projectile land on the ground?
A) 5.0 seconds
B) 9.0 seconds
C) 10 seconds
D) 11 seconds

Question

Quizplus · Accepted Answer

The projectile lands on the ground when its height is equal to zero. So we need to solve the equation -16t^2 + 144t + 160 = 0. Factoring out -16, we get -16(t^2 - 9t - 10) = 0. This can be further factored as -16(t - 10)(t + 1) = 0. Therefore, the projectile lands on the ground after 10 seconds, which is the only positive solution. So the answer is C.

Find All Fixed Points for the Function by Setting the Function