P(x) = -16x^2 + 32x

Question

A model rocket is launching into the air from ground level.The height, in feet,Is modeled by p(x) = -16x^2 +32x, Where X is the number of elapsed seconds. What is the total number of seconds the model rocket will be in the air?

Answer 1

It will be in the air until P(x) is zero.

P(x) = -16x² + 32x = -16x(x - 2)

P(x) = 0 ⇒ x = 0 or x = 2

It starts on the ground at x = 0, so the total time in the air must be x = 2 seconds.