A projectile is thrown upward so that its distance above the ground after t seconds is given by the function h(t) = -16t² + 704t. After how many seconds does the projectile take to reach its maximum height? Show your work for full credit.

h(t) = -16t^2 +704t = -16(t^2 -44t)
Putting in vertex form: -16(t^2 -44t +484) + 704
h(t) = -16(t-22)^2 + 704
It takes 22 seconds to reach the maximum height, which is the vertex of the parabola at (22,704)