A-level · Complex numbers

Complex roots of polynomial equationsExam-style questions

Solving quadratics with a negative discriminant to get a conjugate pair of complex roots; the theorem that complex roots of a real-coefficient polynomial come in conjugate pairs; using one known complex root to find the others and factorise cubics and quartics; and finding the square roots of a + bi by equating real and imaginary parts.

15 questions · A Level level · mark scheme and worked solution on each · no sign-up to try