An event in the Summer Olympics is 10-meter springboard diving. In this event, the height s, in meters, of a diver above the water t seconds after jumping is given by s(t) = –4.9t2 + 7.1t + 10. What is the maximum height that the diver will be above the water? Round to the nearest tenth.

Answer 1

recall that for the general quadratic, max y is at x = -b/2a. In this case, at t=7.1/9.8

Just plug that in to get s.