BONUS QUESTION (extra credit)

 

Fred flops into a pool from a platform 18.75 feet above water. His height above the water in feet $\displaystyle {x}$ seconds into the flop is given by the expression $\displaystyle -{5}{\left({x}-{.5}\right)}^{{2}}+{20}.$ How long will it take Fred to hit the water?

(Hint: set the equation equal to 18.75 and solve the equation).

seconds