The position of a ball projected upward from a height of 364 meters is given by the formula
s=−16t2+45t+364
where t is the number of seconds elapsed. How long will it take for the ball to reach a height of 187 meters above the ground?
you are simply solving the quadratic
187 = -16t^2 + 45t + 364
16t^2 - 45t - 177 = 0
solve by using the formula, one of the answers will probably be negative. Reject it.