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ASMathsAQAPureRevision NotesCoordinate GeometryCirclesFinding the Centre & Radius

Finding the Centre & Radius (AQA AS Maths): Revision Note

Exam code: 7356

Roger B

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Roger B

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AQA Maths: PureCambridge (CIE) Maths: Pure 1OCR Maths A: PureEdexcel Maths: Pure

Finding the centre & radius

How do I find the centre and radius from the equation of a circle?

  • A circle equation in a different form can always be rearranged into (x- a)2 + (y - b)2 = r2 form in order to find the centre and radius

  • This will often involve completing the square

 

Circle Ctr Rad Illustr 1, A Level & AS Level Pure Maths Revision Notes

Examiner Tips and Tricks

Make sure you are able to rearrange circle equations given in the general form x squared space plus space y squared space plus space 2 f x space plus space 2 g y space plus space c space equals space 0 

Circle Ctr Rad general illustr, A Level & AS Level Pure Maths Revision Notes

Worked Example

Circle Ctr Rad Example, A Level & AS Level Pure Maths Revision Notes
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Roger B

Author: Roger B

Expertise: Maths Content Creator

Roger's teaching experience stretches all the way back to 1992, and in that time he has taught students at all levels between Year 7 and university undergraduate. Having conducted and published postgraduate research into the mathematical theory behind quantum computing, he is more than confident in dealing with mathematics at any level the exam boards might throw at you.