Paper 1 · Complex Numbers ⏱ Tested in 5 exam questions since 2015 Lesson 3 of 17

Complex Numbers 3 – Division and Conjugates

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You’ll learn

  • Write down the conjugate z̄ of a complex number by flipping the imaginary sign
  • Show that z·z̄ always produces the real number a² + b²
  • Divide complex numbers by multiplying above and below by the denominator's conjugate
  • Express the result of a division in the form a + bi

Most recent exam questions

  • 2025 P1 Q4(a)
  • 2023 P1 Q3(a) — deferred
  • 2021 P1 Q1(a)
  • 2020 P1 Q2(a)
  • 2020 P1 Q2(b)(i)

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