Home · Unit 3 · Topic 1 · Factorisation of polynomials

Factorisation of polynomials

Understand and use the complex conjugate root theorem for polynomials with real coefficients, e.g. factorise a cubic polynomial with real coefficients given one factor.

u3-t1-s3-d2

Interactive

Conjugate roots come in pairs

manipulative

Drag a non-real root of a real cubic — its conjugate twin is forced so the quadratic factor (and the full cubic) keep real coefficients; break the twin to watch coefficients go complex.

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