Question

PLZ HELP IM NOT UNDERSTAND THISSSSSSSS HELPPPPPPPPPPPPPPPPPPP

A catapult launches a boulder with a velocity of 122 feet per second. The height of the boulder ,H, in feet after t seconds is given by the function h(t)=-16^2+122t+10. What is the boulders maximum height?How long does it take the boulder to reach its maximum height?Round to the nearest hundreth if necessary.
A.)Reaches a maximum height of 15.42 feet after 7.71 seconds
*B.)Reaches a maximum height of 7.71 feet after 3.81 seconds *
C.)Reaches a maximum height of 242.56 feet after 7.62 seconds
*D.)Reaches a maximum height of 242.56 feet after 3.81 seconds*
i think it could either be b or d

Answer 1

Answer: D

Explanation:

The expression for x-value of the vertex is (-b/2a). Doing this will give you the time of 3.8125 seconds.

Just input that value back into the equation and you will get the max height of 242.56 feet.