CAIE P3 2014 November — Question 5

Exam BoardCAIE
ModuleP3 (Pure Mathematics 3)
Year2014
SessionNovember
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicComplex Numbers Arithmetic

5 Throughout this question the use of a calculator is not permitted. The complex numbers \(w\) and \(z\) satisfy the relation $$w = \frac { z + \mathrm { i } } { \mathrm { i } z + 2 }$$
  1. Given that \(z = 1 + \mathrm { i }\), find \(w\), giving your answer in the form \(x + \mathrm { i } y\), where \(x\) and \(y\) are real.
  2. Given instead that \(w = z\) and the real part of \(z\) is negative, find \(z\), giving your answer in the form \(x + \mathrm { i } y\), where \(x\) and \(y\) are real.

5 Throughout this question the use of a calculator is not permitted.
The complex numbers $w$ and $z$ satisfy the relation

$$w = \frac { z + \mathrm { i } } { \mathrm { i } z + 2 }$$

(i) Given that $z = 1 + \mathrm { i }$, find $w$, giving your answer in the form $x + \mathrm { i } y$, where $x$ and $y$ are real.\\
(ii) Given instead that $w = z$ and the real part of $z$ is negative, find $z$, giving your answer in the form $x + \mathrm { i } y$, where $x$ and $y$ are real.

\hfill \mbox{\textit{CAIE P3 2014 Q5}}