At the skateboard park, the hot new attraction is the U-
Dip, a cement structure embedded into the ground.
The cross-sectional view of the U-Dip is a parabola that
dips 15 feet below the ground. The width at ground
level, its widest part, is 40 feet across. Sketch the
cross-sectional view of the U-Dip, and find an equation
of the parabola that models it.