Need to know how to do this problem please, I’m desperate

Question

A rocket is launched from a tower. The height of the rocket, y in feet, is related to the time after launch, x in seconds, by the given equation. Using this equation, find out the time at which the rocket will reach its max,

To the nearest 100th of a second.

Y= -16x² + 188x + 103

Answer 1

This is a downward facing parabola. It will be at its maximum height at the vertex. The x coordinate( which represents time) is at -b/2a or (-188)/(2 x -16) = 188/-32 =5.875 sec rounding to the nearest 100th gives

5.88 sceonds