Paper 2 · Co-ordinate Geometry of the Circle
⏱ Tested in 4 exam questions since 2015
Lesson 5 of 9
The Circle 5 – Intersecting circles/Touching circles
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- Prove two circles touch by comparing |C₁C₂| with R₁ + R₂ and |R₁ − R₂|
- Find the common tangent or chord by setting K₁ = K₂ so x² and y² cancel
- Find the point of contact by solving the tangent with one circle equation
- Prove the centres and the point of contact are collinear using equal slopes
Most recent exam questions
- 2025 P2 Q6(a)(ii) — deferred
- 2024 P2 Q5(a)(ii)
- 2021 P2 Q3(b)(i)
- 2021 P2 Q3(b)(ii)
- 2015 P2 Q4(b)(i)
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