Paper 2 · Co-ordinate Geometry of the Circle ⏱ Tested in 1 exam question since 2023 Lesson 9 of 9

The Circle 9 – Simultaneous Equations

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You’ll learn

  • Find the circle through three points by subbing each into x²+y²+2gx+2fy+c = 0
  • Solve the resulting 3×3 linear system in g, f and c by elimination
  • Pick pivot equations from points with a zero coordinate to cut the algebra

Most recent exam questions

  • 2023 Paper 2 Q4(b) — find the equation of a circle given three points on it — exploit the geometric observati…

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