You are Here: Home >< Maths

# Lines in a circle Watch

1. Could someone guide me towards the answer:

Q) A chord of a circle passes through the points P(-2,-3) and Q(6,1). Find the equation of the diameter of the circle perpendicular to this chord.

I get that the gradient of the line perpendicular is the inverse reciprocal but I've just got mind block past that.
2. (Original post by SuchBants)
Could someone guide me towards the answer:

Q) A chord of a circle passes through the points P(-2,-3) and Q(6,1). Find the equation of the diameter of the circle perpendicular to this chord.

I get that the gradient of the line perpendicular is the inverse reciprocal but I've just got mind block past that.
The diameter is the perpendicular BISECTOR of any chord.
3. (Original post by SuchBants)
Could someone guide me towards the answer:

Q) A chord of a circle passes through the points P(-2,-3) and Q(6,1). Find the equation of the diameter of the circle perpendicular to this chord.

I get that the gradient of the line perpendicular is the inverse reciprocal but I've just got mind block past that.
Okay so you know the gradient of the diameter then. Now you can find the point through which the diameter must pass because the diameter must go through the middle of the chord. You can work out the co-ordinates of the middle of the chord. Then you have enough info for the line equation.

(Original post by ValerieKR)
The diameter is the perpendicular BISECTOR of any chord.
That really doesn't help in his situation, but I'm a bit fussed with the wording. Never mind, though.
4. (Original post by RDKGames)
That really doesn't help in his situation, but I'm a bit fussed with the wording. Never mind, though.
They know the gradient - bisector gives the constant.
5. (Original post by ValerieKR)
The diameter is the perpendicular BISECTOR of any chord.
Thank you, I wasn't aware of this

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: September 1, 2016
Today on TSR

### Last-minute PS help

100s of personal statements examples here

### Loneliness at uni

Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams

## Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.