Question

A hovercraft takes off from a platform.

Its height (in meters), x seconds after takeoff, is modeled by
h(x) = -(x – 11)(x + 3)
How many seconds after takeoff will the hovercraft land on the ground?
___________ seconds

Answer 1

11 seconds

Explanation:

The value of h(x) is zero when either of the factors is zero:

x -11 = 0 ⇒ x = 11

x +3 = 0 ⇒ x = -3

The solution x = -3 is not in the practical domain of the model, so the only reasonable solution is x = 11.

The hovercraft will land 11 seconds after takeoff.