H (x) = - (x-11) (x+3)

what is the height of the hovercraft at the time of takeoff?

33 feet

Step-by-step explanation:

height of hovercraft x seconds after takeoff = h (x) = - (x - 11) (x + 3)

We want to know the height of the hovercraft 0 seconds after takeoff.

height of hovercraft 0 seconds after takeoff = h (0) = - (0 - 11) (0 + 3) = - (-11) (3) = 33

So ...

The height of the hovercraft at the time of takeoff is 33 meters.