Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    1
    ReputationRep:
    A circle passes through the points A(-5,4), B(-3,-2), C(1,10).
    Find the point of intersection of the perpendicular bisectors of AB and BC.
    Find the equation of the circle.

    Help on this pls
    Offline

    2
    ReputationRep:
    (Original post by Aksa09)
    A circle passes through the points A(-5,4), B(-3,-2), C(1,10).
    Find the point of intersection of the perpendicular bisectors of AB and BC.
    Find the equation of the circle.

    Help on this pls
    Write equations for the lines AB and BC, then find equations of perpendicular bisectors of these lines then, as the points are in a circle, the perpendicular bisector to a chord on a circle contains the radius (passes through the centre of the circle). So the perpendicular bisector a will intersect at the centre of the circle. Then just use the standard form for the equation of a circle and plug in the centre coordinates and then find radius.
    • Thread Starter
    Offline

    1
    ReputationRep:
    (Original post by Ano123)
    Write equations for the lines AB and BC, then find equations of perpendicular bisectors of these lines then, as the points are in a circle, the perpendicular bisector to a chord on a circle contains the radius (passes through the centre of the circle). So the perpendicular bisector a will intersect at the centre of the circle. Then just use the standard form for the equation of a circle and plug in the centre coordinates and then find radius.
    How do I find equation of the perpendicular bisectors of these lines?
    Offline

    2
    ReputationRep:
    (Original post by Aksa09)
    How do I find equation of the perpendicular bisectors of these lines?
    Well work out the gradient of the lines AB and BC and then do what you normally would to find a line that is perpendicular to another - remember that the perpendicular bisector will go through the midpoints of the lines AB and BC.
    Offline

    20
    ReputationRep:
    if two lines are perpendicular the product of their gradients is -1
    Offline

    22
    ReputationRep:
    And the bisector means that the perpendicular bisector will go through the midpoint of the line.
 
 
 
  • 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
    Brussels sprouts
    Useful resources

    Make your revision easier

    Maths

    Maths Forum posting guidelines

    Not sure where to post? Read the updated guidelines here

    Equations

    How to use LaTex

    Writing equations the easy way

    Student revising

    Study habits of A* students

    Top tips from students who have already aced their exams

    Study Planner

    Create your own Study Planner

    Never miss a deadline again

    Polling station sign

    Thinking about a maths degree?

    Chat with other maths applicants

    Can you help? Study help unanswered threads

    Groups associated with this forum:

    View associated groups
  • 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

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