| Exam Board | Edexcel |
| Module | F1 (Further Pure Mathematics 1) |
| Year | 2016 |
| Session | January |
| Marks | 9 |
| Paper | Download PDF ↗ |
| Topic | Complex Numbers Arithmetic |
| Type | Multiplication and powers of complex numbers |
| Difficulty | Moderate -0.3 This is a straightforward Further Maths question testing basic complex number operations: multiplication, division by conjugate, and solving a modulus equation. Part (a) is routine multiplication, part (b) requires multiplying by conjugate (standard technique), and part (c) involves expanding |z+k|, squaring both sides, and solving a quadratic. All are standard textbook exercises with no novel insight required, making it slightly easier than average even for Further Maths. |
| Spec | 4.02a Complex numbers: real/imaginary parts, modulus, argument4.02c Complex notation: z, z*, Re(z), Im(z), |z|, arg(z)4.02e Arithmetic of complex numbers: add, subtract, multiply, divide |
1.
$$z = 3 + 2 \mathrm { i } , \quad w = 1 - \mathrm { i }$$
Find in the form \(a + b \mathrm { i }\), where \(a\) and \(b\) are real constants,
- \(z w\)
- \(\frac { z } { w ^ { * } }\), showing clearly how you obtained your answer.
Given that
$$| z + k | = \sqrt { 53 } \text {, where } k \text { is a real constant }$$
- find the possible values of \(k\).