11.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{0e7cab3d-c1e6-4420-93b4-eca5af704432-10_766_791_283_701}
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\caption{Figure 1}
\end{figure}
The Argand diagram, shown in Figure 1, shows a circle \(C\) and a half-line \(l\).
- Write down the equation of the locus of points represented in the complex plane by
- the circle \(C\),
- the half-line \(l\).
- Use set notation to describe the set of points that lie on both \(C\) and \(l\).
- Find the complex numbers that lie on both \(C\) and \(l\), giving your answers in the form \(a + \mathrm { i } b\), where \(a , b \in \mathbb { R }\).