a stone bridge has a parabolic arch what a niver flows
onder it. at the water level the arch is 24 ft wide. the peak
of the arch is 40 ft above the water
& using the left end of the arch (where it meets the water)
as the origin, find an emation for the arch. that is, find
an equation that gives the beight y (in feet) above the
water of a point on the arch as a function the point's
position x (in feet) in relation to the left endpoint