Hi,

I would like to ask your help, I can't figure out how to do that question.

A concrete bridge over a river has an underside in the shape of a parabolic arch. At the water level, the arch is 30m wide. It has a maximum height of

10m above the water. The minimum vertical thickness of the concrete is 1.5m

a)Find algebric relation that represents the shape of the arch.

When I tries my answer was y=1.5(x-25)+10 was that right?

b)What is the vertical thickness of the concrete 3m from the centre of the arch?

c)If the water level rises 2m, how wide will the arch be at this new level?

Thank you very much!