Proving Locus of Middle Points of Chords on Parabola

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In summary, the conversation discusses a homework problem where the locus of middle points of all chords of a parabola ##y^2=4ax##, which pass through the vertex, needs to be proven to be the parabola ##y^2=2ax##. The attempt at a solution involves finding the midpoint of the line joining the vertex and a point on the parabola, but the question remains on how to eliminate h from the equations. The solution is eventually provided by another user.
  • #1
Saitama
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Homework Statement


Prove that the locus of middle points of all chords of the parabola ##y^2=4ax## which are drawn through the vertex is the parabola ##y^2=2ax##.


Homework Equations





The Attempt at a Solution


The mid-point of the line joining the vertex and a point ##(h,2\sqrt{ah})## on parabola is ##(h/2,\sqrt{ah})## but what am I supposed to do with this? :confused:
 
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  • #2
Pranav-Arora said:

Homework Statement


Prove that the locus of middle points of all chords of the parabola ##y^2=4ax## which are drawn through the vertex is the parabola ##y^2=2ax##.


Homework Equations





The Attempt at a Solution


The mid-point of the line joining the vertex and a point ##(h,2\sqrt{ah})## on parabola is ##(h/2,\sqrt{ah})## but what am I supposed to do with this? :confused:

You have ##x=h/2## and ##y=\sqrt{ah}##. Eliminate h?
 
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  • #3
I like Serena said:
You have ##x=h/2## and ##y=\sqrt{ah}##. Eliminate h?

Woops, I was trying this question from the last night and I couldn't even notice that. Very foolish of me. :redface:

Thank you ILS! :smile:
 

What is a locus on a parabola?

A locus on a parabola refers to the set of all points on the parabola that satisfy a specific condition or property. In this case, the locus is the set of middle points of chords on the parabola.

How do you prove the locus of middle points of chords on a parabola?

The locus of middle points of chords on a parabola can be proven using the distance formula. This involves finding the distance between the midpoint of a chord and the focus of the parabola. If the distance is equal to the distance between the midpoint and the directrix of the parabola, then the point lies on the locus.

What is the significance of proving the locus of middle points of chords on a parabola?

Proving the locus of middle points of chords on a parabola allows us to better understand the properties of the parabola and its relationship to its focus and directrix. It also has practical applications in fields such as engineering and physics.

Can the locus of middle points of chords on a parabola be used to find the equation of the parabola?

Yes, the locus of middle points of chords on a parabola can be used to find the equation of the parabola. This is because the locus is a set of points that satisfy a specific condition, which can be translated into an algebraic equation.

Are there any other methods to prove the locus of middle points of chords on a parabola?

Yes, besides using the distance formula, there are other methods to prove the locus of middle points of chords on a parabola. These include using the properties of the focus and directrix, as well as using the definition of a parabola as the locus of points that are equidistant from a fixed point and a fixed line.

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