Edexcel FP2 — Question 9 7 marks

Exam BoardEdexcel
ModuleFP2 (Further Pure Mathematics 2)
Marks7
PaperDownload PDF ↗
TopicComplex Numbers Argand & Loci
TypeCircle of Apollonius locus
DifficultyStandard +0.3 This is a straightforward FP2 question testing standard locus techniques and transformations. Part (a) requires algebraic manipulation of modulus equations to find a circle (Apollonius circle), which is routine for FP2 students. Part (b) is direct application of combining transformations. Both parts are textbook exercises requiring recall and standard methods rather than problem-solving or insight.
Spec4.02k Argand diagrams: geometric interpretation4.02m Geometrical effects: multiplication and division

  1. The point \(P\) represents a complex number \(z\) in an Argand diagram. Given that $$|z - 2i| = 2|z + i|,$$
    1. find a cartesian equation for the locus of \(P\), simplifying your answer. [2]
    2. sketch the locus of \(P\). [3]
  2. A transformation \(T\) from the \(z\)-plane to the \(w\)-plane is a translation \(-7 + 11i\) followed by an enlargement with centre the origin and scale factor \(3\). Write down the transformation \(T\) in the form $$w = az + b, \quad a, b \in \mathbb{C}.$$ [2]

\begin{enumerate}[label=(\alph*)]
\item The point $P$ represents a complex number $z$ in an Argand diagram. Given that
$$|z - 2i| = 2|z + i|,$$
\begin{enumerate}[label=(\roman*)]
\item find a cartesian equation for the locus of $P$, simplifying your answer. [2]
\item sketch the locus of $P$. [3]
\end{enumerate}

\item A transformation $T$ from the $z$-plane to the $w$-plane is a translation $-7 + 11i$ followed by an enlargement with centre the origin and scale factor $3$.

Write down the transformation $T$ in the form
$$w = az + b, \quad a, b \in \mathbb{C}.$$ [2]
\end{enumerate}

\hfill \mbox{\textit{Edexcel FP2  Q9 [7]}}