Billy shoots an arrow from 10 feet above the ground. The height of this arrow can be expressed by the equation $h=10-23t-10t^2$, where $t$ is time in seconds. If the center of a target is raised 5 feet off the ground, in how many seconds must the arrow reach the target in order for Billy to hit the bulls eye?
Substitute h = 5 and solve the equation for t
5 = 10-23t-10t^2
0 = 5 -23t-10t^2 Use quadratic formula to find t = .2 sec