<h2>Explanation:</h2>
In this problem we have a pumpkin is launched from the top of a 20 foot tall platform at an initial velocity of 84 feet per second. So the height, h, of the pumpkin at time t seconds after the launch can be modeled by the equation:
So this is the equation of a parabola. The maximum of this parabola occurs at its vertex. So let's find this vertex:
Finally, the maximum occurs at time 2.625 seconds when the height is 130.25m