Question

A hovercraft takes off from a platform.
Its height (in meters), xxx seconds after takeoff, is modeled by:
h(x)=-3(x-3)^2+108h(x)=−3(x−3)
2
+108h, left parenthesis, x, right parenthesis, equals, minus, 3, left parenthesis, x, minus, 3, right parenthesis, squared, plus, 108
How many seconds after takeoff will the hovercraft land on the ground?

Answer 1

The correct answer

After 11 seconds the hovercraft will land on ground

Step-by-step explanation:

=>Given function that shows the height of a hovercraft,

Where,

x = number of second.

When the hovercraft land the ground,

By zero product property,

x - 11 = 0 or x + 3 = 0

⇒ x = 11 or x = -3 ( not possible ),

Hence, after 11 seconds the hovercraft will land on ground

Answer 2

Answer:

the height of the hovercraft at the time of takeoff is 81 meters

Step-by-step explanation:

From Khan academy

h(x)=−3(x−3)²+108

Substitute x with a zero

-3(0-3)²+108

which equals 81.