- #1

ahmadmz

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## Homework Statement

A parabolic arch spans a stream 200 feet wide. How high

must the arch be above the stream to give a minimum

clearance of 40 feet over a channel in the center that is

120 feet wide?

## Homework Equations

## The Attempt at a Solution

They are asking for the k value right?

If I place the parabola starting from x=0,y=0 then the vertex is at (100,40+n).

When x=40,y=40. x=160,y=40 I want to find out what y is when x=100.

So I used the equation (x-h)^2 = a(y-k)

(x-100)^2 = a(y-(40+n)) After using x=40 ,y=40 I get n=-3600/a And now I have no idea what to do .. Am I doing this right?