Pre-U Pre-U 9795 Specimen — Question 2

Exam BoardPre-U
ModulePre-U 9795 (Pre-U Further Mathematics)
SessionSpecimen
TopicComplex Numbers Argand & Loci
TypeRegion shading with multiple inequalities
DifficultyModerate -0.3 This is a standard complex numbers loci question requiring students to sketch a circle centered at origin with radius 4 and a half-line from -4i at angle π/4, then shade the intersection region. While it requires understanding of modulus and argument, it's a routine textbook exercise with no novel problem-solving or proof required, making it slightly easier than average.
Spec4.02k Argand diagrams: geometric interpretation4.02o Loci in Argand diagram: circles, half-lines

2
  1. On a single Argand diagram, sketch and clearly label each of the following loci:
    1. \(| z | = 4\),
    2. \(\quad \arg ( z + 4 \mathrm { i } ) = \frac { 1 } { 4 } \pi\).
    3. On the same Argand diagram, shade the region \(R\) defined by the inequalities $$| z | \leqslant 4 \quad \text { and } \quad 0 \leqslant \arg ( z + 4 i ) \leqslant \frac { 1 } { 4 } \pi$$

2 (i) On a single Argand diagram, sketch and clearly label each of the following loci:
\begin{enumerate}[label=(\alph*)]
\item $| z | = 4$,
\item $\quad \arg ( z + 4 \mathrm { i } ) = \frac { 1 } { 4 } \pi$.\\
(ii) On the same Argand diagram, shade the region $R$ defined by the inequalities

$$| z | \leqslant 4 \quad \text { and } \quad 0 \leqslant \arg ( z + 4 i ) \leqslant \frac { 1 } { 4 } \pi$$
\end{enumerate}

\hfill \mbox{\textit{Pre-U Pre-U 9795  Q2}}