SPS SPS ASFM 2020 May — Question 1 5 marks

Exam BoardSPS
ModuleSPS ASFM (SPS ASFM)
Year2020
SessionMay
Marks5
TopicComplex Numbers Argand & Loci
TypeModulus-argument form conversion
DifficultyEasy -1.3 This question tests basic complex number definitions (modulus, argument, conjugate) and geometric interpretation. Part (a) requires only direct application of formulas with no problem-solving, while part (b) asks for standard knowledge that conjugates are reflections in the real axis. This is routine recall with minimal computational challenge, significantly easier than average A-level questions.
Spec4.02a Complex numbers: real/imaginary parts, modulus, argument4.02k Argand diagrams: geometric interpretation

You are given that \(z = 3 - 4\mathrm{i}\).
  1. Find
    [3] On an Argand diagram the complex number \(w\) is represented by the point \(A\) and \(w^*\) is represented by the point \(B\).
  2. Describe the geometrical relationship between the points \(A\) and \(B\). [2]

You are given that $z = 3 - 4\mathrm{i}$.

\begin{enumerate}[label=(\alph*)]
\item Find
\begin{itemize}
\item $|z|$,
\item $\arg(z)$,
\item $z^*$.
\end{itemize}
[3]

On an Argand diagram the complex number $w$ is represented by the point $A$ and $w^*$ is represented by the point $B$.

\item Describe the geometrical relationship between the points $A$ and $B$. [2]
\end{enumerate}

\hfill \mbox{\textit{SPS SPS ASFM 2020 Q1 [5]}}