13. A diving board is 5 feet above the water level of the pool. A swimmer steps off the board into the water. The function d
-16x² + 5 gives
the distance d of the swimmer's feet above the water level after x seconds.
a. When do the swimmer's feet hit the water?
b. When will the swimmer's feet be 4 feet below the water level?
c. The high diving board is 15 feet above the water level of the pool. How
could you translate the function d = –16x2 + 5 to adjust for the height
of the high diving board?