The height, in meters, of a rocket above the ground seconds after launch is modeled by a quadratic function. The rocket reaches its maximum height of meters after seconds and lands on the ground seconds after launch. At what time(s), in seconds, was the rocket at a height of meters?
4.2 and 15.8
5.0 and 15.0
6.4 and 13.6
7.5 and 12.5
