Paper 1 · Complex Numbers
⏱ Tested in 1 exam question since 2025
Lesson 9 of 17
Complex Numbers 9 – Cubic equations
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- Write down a cubic's second complex root for free using the conjugate-pair theorem
- Build the quadratic factor z² − (sum)z + (product) from the conjugate pair
- Long-divide the cubic (padding missing terms with 0) to extract the real root
- Given a real root instead, divide by its linear factor and solve for the complex pair
Most recent exam questions
- 2025 P1 Q3(c) — deferred
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