Hi, how would I find the equation of a bridge (parabola) if the river is 18m wide, and the arch of the parabola must be anchored on the ground 3m back from the riverbanks. The bridge's arch must reach a maximum height of 22m above the river. Thanks.

Hi, how would I find the equation of a bridge (parabola) if the river is 18m wide, and the arch of the parabola must be anchored on the ground 3m back from the riverbanks. The bridge's arch must reach a maximum height of 22m above the river. Thanks.