posted by Aaron .
The equation h = -16t^2 + 32t + 9 gives the height of a ball, h, in feet above the ground, at t seconds after the ball is thrown upward. How many seconds after the ball is thrown will it reach its maximum height? What is its maximum height?
find the vertex of the parabola.
The t of the vertex tells you when it reached the maximum height, the h tells you what that height is.