For this case we have the following equation: h = -16t ^ 2 + 32t + 6 Deriving we have: h '= -32t + 32 We equal zero and clear t: -32t + 32 = 0 32t = 32 t = 32/32 t = 1 s Then, the maximum height is given by: h (1) = -16 * (1) ^ 2 + 32 * (1) + 6 h (1) = 22 feet Answer: It takes the ball to reach its maximum height about: t = 1 s The ball's maximum height is: h (1) = 22 feet