- #1

utkarshakash

Gold Member

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**Tangent and normal parabola**

## Homework Statement

P is a point 't' on the parabola y^2=4ax and PQ is a focal chord. PT is a tangent at P and QN is a normal at Q. The minimum distance between PT and QN is equal to

## Homework Equations

## The Attempt at a Solution

I think minimum distance will occur when the chord PQ is parallel to Y-axis. In other words, the normal at Q will be parallel to the tangent at P. In that case I can apply the formula for calculating the distance between two parallel lines. But this does not give correct answer. I also thought about 0 but I don't think these questions have such simple answers.

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