A ball is thrown straight up from the top of a building 128 ft tall with an initial velocity of 80 ft per second. The height
s(t) (in feet)
of the ball from the ground, at time t (in seconds), is given by
s(t) = 128 + 80t − 16t^2.
Find the maximum height attained by the ball.
as with all parabolas, the vertex is at t = -b/2a = 80/32
find s there.