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Complex numbers: Edexcel A‑Level Further Maths questions

Every Edexcel A-Level Further Maths exam question on CP.2 Complex numbers, 2018–2025, with its mark scheme and examiner’s report.

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824 questions

  1. Q3

    June 2025 · Core Pure 1

    The whole paper ↗
    June 2025 Core Pure 1, question 3: The complex number z a b i where a and b are real constants. Given that z z* is purely imaginary, (a) show that a b 2 2 = (2) Given also that zz* = 50 (b) deter
  2. Q6

    June 2025 · Core Pure 1

    The whole paper ↗
    June 2025 Core Pure 1, question 6: f (z) = z3 + az2 + bz + c where a, b and c are real constants The roots of the equation f (z) = 0 are z1, z2 and z3 When plotted on an Argand diagram, the point
  3. Q10

    June 2025 · Core Pure 1

    The whole paper ↗
    June 2025 Core Pure 1, question 10: (a) Given that, for n ∈ z z n n n 1 2cos θ z z n n n 1 2isin θ show that 8 4 4 2 3 4 sin cos cos θ θ θ (5) O y R x Figure 1 Figure 2 Figure 1 shows the central
  4. Q1

    June 2025 · Core Pure 2

    The whole paper ↗
    June 2025 Core Pure 2, question 1: In this question you must show all stages of your working. Solutions relying entirely on calculator technology are not acceptable. Given that z 2 2 3i and w 1 3
  5. Q4

    June 2025 · Core Pure 2

    The whole paper ↗
    June 2025 Core Pure 2, question 4: (i) z a b 1 i and z c d 2 i where a, b, c and d are real constants. Given that • b d > • z z 1 2 + is real • z1 13 = • z2 5 = • Re z z 2 1 2 show that a = 2 and
  6. Q1

    June 2025 · AS Core Pure

    The whole paper ↗
    June 2025 AS Core Pure, question 1: z = 3 – 3i (a) Write z in the form r(cos θ + i sin θ) where –π < θ  π (2) (b) Show and label on a single Argand diagram (i) the point P representing z (ii) the
  7. Q2

    June 2025 · AS Core Pure

    The whole paper ↗
    June 2025 AS Core Pure, question 2: In this question you must show all stages of your working. Solutions relying entirely on calculator technology are not acceptable. f(z) = 4z 3 – 12z 2 – 95z + 3
  8. Q5

    June 2025 · AS Core Pure

    The whole paper ↗
    June 2025 AS Core Pure, question 5: A complex number z is represented by the point P in the complex plane. Given that z satisfies | z – 1 | = 1 (a) sketch on an Argand diagram the locus of P as z
  9. Q1

    June 2024 · Core Pure 1

    The whole paper ↗
    June 2024 Core Pure 1, question 1: f(z) = z z az bz 4 3 2 6 145 where a and b are real constants. Given that 2 + 5i is a root of the equation f(z) = 0 (a) determine the other roots of the equatio
  10. Q4

    June 2024 · Core Pure 1

    The whole paper ↗
    June 2024 Core Pure 1, question 4: The complex number z = e iθ, where θ is real. (a) Show that z n + 1 zn ≡2 cos nθ where n is a positive integer. (2) (b) Show that cos 5 θ = 1 16 (cos 5θ + 5 cos
  11. Q5

    June 2024 · Core Pure 2

    The whole paper ↗
    June 2024 Core Pure 2, question 5: The locus C is given by z 4 4 The locus D is given by arg 3 π z (a) Sketch, on the same Argand diagram, the locus C and the locus D (4) The set of points A is d
  12. Q7

    June 2024 · Core Pure 2

    The whole paper ↗
    June 2024 Core Pure 2, question 7: (a) Determine the roots of the equation z 6 = 1 giving your answers in the form e iθ where 0  θ < 2π (2) (b) Show the roots of the equation in part (a) on a si
  13. Q5

    June 2024 · AS Core Pure

    The whole paper ↗
    June 2024 AS Core Pure, question 5: Given that on an Argand diagram the locus of points defined by | z + 5 – 12i | = 10 is a circle, (a) write down, (i) the coordinates of the centre of this circl
  14. Q3

    June 2023 · Core Pure 1

    The whole paper ↗
    June 2023 Core Pure 1, question 3: In this question you must show all stages of your working. Solutions relying on calculator technology are not acceptable. z1 = –4 + 4i (a) Express z1 in the for
  15. Q5

    June 2023 · Core Pure 2

    The whole paper ↗
    June 2023 Core Pure 2, question 5: The points representing the complex numbers z1 = 35 – 25i and z2 = –29 + 39i are opposite vertices of a regular hexagon, H, in the complex plane. The centre of
  16. Q8

    June 2023 · Core Pure 2

    The whole paper ↗
    June 2023 Core Pure 2, question 8: Given that a cubic equation has three distinct roots that all lie on the same straight line in the complex plane, (a) describe the possible lines the roots can
  17. Q2

    June 2023 · AS Core Pure

    The whole paper ↗
    June 2023 AS Core Pure, question 2: f (z) = z 3 + az 2 + bz + 175 where a and b are real constants Given that –3 + 4i is a root of the equation f(z) = 0 (a) determine the value of a and the value
  18. Q4

    June 2023 · AS Core Pure

    The whole paper ↗
    June 2023 AS Core Pure, question 4: (i) (a) Show that 2 3 5 1 i i i k( ) where k is a constant to be determined. (Solutions relying on calculator technology are not acceptable.) (3) Given that • n
  19. Q7

    June 2023 · AS Core Pure

    The whole paper ↗
    June 2023 AS Core Pure, question 7: (i) Shade, on an Argand diagram, the set of points for which | z – 3 |  | z + 6i | (3) (ii) Determine the exact complex number w which satisfies both arg (w –
  20. Q1

    June 2022 · Core Pure 1

    The whole paper ↗
    June 2022 Core Pure 1, question 1: f(z) = z3 + az + 52 where a is a real constant Given that 2 – 3i is a root of the equation f(z) = 0 (a) write down the other complex root. (1) (b) Hence (i) sol
All 39 questions on Complex numbers, as a list
  1. June 2025, Core Pure 1, Q3 (5 marks): The complex number z a b i where a and b are real constants. Given that z z* is purely imaginary, (a) show that a b 2 2 = (2) Given also that zz* = 50 (b) deter
  2. June 2025, Core Pure 1, Q6 (5 marks): f (z) = z3 + az2 + bz + c where a, b and c are real constants The roots of the equation f (z) = 0 are z1, z2 and z3 When plotted on an Argand diagram, the point
  3. June 2025, Core Pure 1, Q10 (12 marks): (a) Given that, for n ∈ z z n n n 1 2cos θ z z n n n 1 2isin θ show that 8 4 4 2 3 4 sin cos cos θ θ θ (5) O y R x Figure 1 Figure 2 Figure 1 shows the central
  4. June 2025, Core Pure 2, Q1 (6 marks): In this question you must show all stages of your working. Solutions relying entirely on calculator technology are not acceptable. Given that z 2 2 3i and w 1 3
  5. June 2025, Core Pure 2, Q4 (10 marks): (i) z a b 1 i and z c d 2 i where a, b, c and d are real constants. Given that • b d > • z z 1 2 + is real • z1 13 = • z2 5 = • Re z z 2 1 2 show that a = 2 and
  6. June 2025, AS Core Pure, Q1 (6 marks): z = 3 – 3i (a) Write z in the form r(cos θ + i sin θ) where –π < θ  π (2) (b) Show and label on a single Argand diagram (i) the point P representing z (ii) the
  7. June 2025, AS Core Pure, Q2 (7 marks): In this question you must show all stages of your working. Solutions relying entirely on calculator technology are not acceptable. f(z) = 4z 3 – 12z 2 – 95z + 3
  8. June 2025, AS Core Pure, Q5 (8 marks): A complex number z is represented by the point P in the complex plane. Given that z satisfies | z – 1 | = 1 (a) sketch on an Argand diagram the locus of P as z
  9. June 2024, Core Pure 1, Q1 (9 marks): f(z) = z z az bz 4 3 2 6 145 where a and b are real constants. Given that 2 + 5i is a root of the equation f(z) = 0 (a) determine the other roots of the equatio
  10. June 2024, Core Pure 1, Q4 (10 marks): The complex number z = e iθ, where θ is real. (a) Show that z n + 1 zn ≡2 cos nθ where n is a positive integer. (2) (b) Show that cos 5 θ = 1 16 (cos 5θ + 5 cos
  11. June 2024, Core Pure 2, Q5 (9 marks): The locus C is given by z 4 4 The locus D is given by arg 3 π z (a) Sketch, on the same Argand diagram, the locus C and the locus D (4) The set of points A is d
  12. June 2024, Core Pure 2, Q7 (9 marks): (a) Determine the roots of the equation z 6 = 1 giving your answers in the form e iθ where 0  θ < 2π (2) (b) Show the roots of the equation in part (a) on a si
  13. June 2024, AS Core Pure, Q5 (10 marks): Given that on an Argand diagram the locus of points defined by | z + 5 – 12i | = 10 is a circle, (a) write down, (i) the coordinates of the centre of this circl
  14. June 2023, Core Pure 1, Q3 (10 marks): In this question you must show all stages of your working. Solutions relying on calculator technology are not acceptable. z1 = –4 + 4i (a) Express z1 in the for
  15. June 2023, Core Pure 2, Q5 (9 marks): The points representing the complex numbers z1 = 35 – 25i and z2 = –29 + 39i are opposite vertices of a regular hexagon, H, in the complex plane. The centre of
  16. June 2023, Core Pure 2, Q8 (11 marks): Given that a cubic equation has three distinct roots that all lie on the same straight line in the complex plane, (a) describe the possible lines the roots can
  17. June 2023, AS Core Pure, Q2 (7 marks): f (z) = z 3 + az 2 + bz + 175 where a and b are real constants Given that –3 + 4i is a root of the equation f(z) = 0 (a) determine the value of a and the value
  18. June 2023, AS Core Pure, Q4 (8 marks): (i) (a) Show that 2 3 5 1 i i i k( ) where k is a constant to be determined. (Solutions relying on calculator technology are not acceptable.) (3) Given that • n
  19. June 2023, AS Core Pure, Q7 (9 marks): (i) Shade, on an Argand diagram, the set of points for which | z – 3 |  | z + 6i | (3) (ii) Determine the exact complex number w which satisfies both arg (w –
  20. June 2022, Core Pure 1, Q1 (6 marks): f(z) = z3 + az + 52 where a is a real constant Given that 2 – 3i is a root of the equation f(z) = 0 (a) write down the other complex root. (1) (b) Hence (i) sol
  21. June 2022, Core Pure 1, Q7 (7 marks): Given that z = a + bi is a complex number where a and b are real constants, (a) show that zz* is a real number. (2) Given that • zz* = 18 • z z* = 7 9 + 4 2 9 i
  22. June 2022, Core Pure 1, Q8 (12 marks): (a) Given zn + 1 zn = 2 cos nθ n ∈  show that 32 cos6 θ ≡ cos 6θ + 6 cos 4θ + 15 cos 2θ + 10 (5) y x O x = –4 x = 4 R Figure 1 Figure 2 Figure 1 shows a solid
  23. June 2022, Core Pure 2, Q1 (3 marks): A student was asked to answer the following: For the complex numbers z1 = 3 – 3i and z2 = 3 + i , find the value of arg z z 1 2     The student’s attempt
  24. June 2022, Core Pure 2, Q4 (6 marks): (i) Given that z1 = 6e i 3 π and z2 = 6 5 i 6 3e π show that z1 + z2 = 12e 2 i 3 π (3) (ii) Given that arg(z – 5) = 2 3 π determine the least value of ½z½ as z
  25. June 2022, AS Core Pure, Q2 (10 marks): (a) Express the complex number w = 4 3 − 4i in the form r (cos θ + i sin θ) where r > 0 and −π < θ  π (4) (b) Show, on a single Argand diagram, (i) the point r
  26. November 2021, Core Pure 2, Q1 (5 marks): Given that 1 2 3 cos isin 3 3 2 cos isin 12 12 π π z π π z       = +                   = −             (a) write down the ex
  27. November 2021, Core Pure 2, Q8 (11 marks): (i) The point P is one vertex of a regular pentagon in an Argand diagram. The centre of the pentagon is at the origin. Given that P represents the complex numbe
  28. November 2021, Core Pure 2, Q9 (8 marks): (a) Given that | z | < 1 , write down the sum of the infinite series 1 + z + z2 + z3 + … (1) (b) Given that z = 1 2 (cos θ + i sin θ) , (i) use the answer to pa
  29. November 2020, Core Pure 1, Q1 (10 marks): f ( z ) = 3z3 + pz2 + 57z + q where p and q are real constants. Given that 3 2 2 − i is a root of the equation f(z) = 0 (a) show all the roots of f(z) = 0 on a
  30. November 2020, Core Pure 2, Q2 (9 marks): In an Argand diagram, the points A and B are represented by the complex numbers −3 + 2i and 5 − 4i respectively. The points A and B are the end points of a diam
  31. November 2020, Core Pure 2, Q4 (10 marks): (a) Use de Moivre’s theorem to prove that sin 7θ = 7 sin θ − 56 sin3 θ + 112 sin5 θ − 64 sin7 θ (5) (b) Hence find the distinct roots of the equation 1 + 7x − 5
  32. November 2020, AS Core Pure, Q2 (8 marks): Given that 1 1 2 1 2 2 3i 39 2 arg( ) 4 = + = = z z z π z z where z1 and z2 are complex numbers, (a) write z1 in the form r(cos θ + i sin θ) Give the exact valu
  33. November 2020, AS Core Pure, Q7 (6 marks): f(z) = z4 + az3 + bz2 + cz + d where a, b, c and d are real constants. The equation f(z) = 0 has complex roots z1, z2, z3 and z4 When plotted on an Argand diagr
  34. November 2020, AS Core Pure, Q10 (7 marks): Given that there are two distinct complex numbers z that satisfy { } 3 : 3 5i 2 :arg( 2) 4 π z z r z z   − − = ∩ − =     determine the exact range of valu
  35. June 2019, Core Pure 1, Q1 (9 marks): I ௘z௘  z4 + az3 + bz2 + cz + d where a, b, c and d are real constants.  *LYHQWKDWíLDQGíLDUHWZRURRWVRIWKHHTXDWLRQI ௘z௘    D  VKRZDO
  36. June 2019, Core Pure 2, Q4 (8 marks): The infinite series C and S are defined by C = cos ș + 1 2 cos 5ș + 1 4 cos 9ș + 1 8 cos 13ș + … S = sin ș + 1 2 sin 5ș + 1 4 sin 9ș + 1 8 sin 13ș + … Given tha
  37. June 2019, Core Pure 2, Q6 (9 marks): In an Argand diagram, the points A, B and C are the vertices of an equilateral triangle with its centre at the origin. The point A represents the complex number
  38. June 2018, AS Core Pure, Q3 (9 marks): (a) Shade on an Argand diagram the set of points { } ( ) 3 : 1 i 3 : arg 2 4 4 π π z z z z   − − ∩ −     C C ∈ ∈ (5) The complex number w satisfies ( ) 1
  39. June 2018, AS Core Pure, Q7 (7 marks): f (z) = z3 + z2 + pz + q where p and q are real constants. The equation f (z) = 0 has roots z1 , z2 and z3 When plotted on an Argand diagram, the points represe

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