The equation #h=16t^2+47t+3# gives the height h, in feet, of a football as a function of time t, in seconds, after it is kicked. What is the maximum height the football reaches?
The equation h = 16t^2 + 47t + 3, with a = 16 > 0, wrongly represents
the ball's trajectory. In this case, a > 0, the parabola opens upward. There is a minimum, instead of a maximum.
In order to have a maximum, a should be negative (a < 0).