Edexcel FP1 — Question 19 11 marks

Exam BoardEdexcel
ModuleFP1 (Further Pure Mathematics 1)
Marks11
PaperDownload PDF ↗
TopicComplex Numbers Argand & Loci
TypeComplex arithmetic operations
DifficultyModerate -0.3 This is a straightforward multi-part complex numbers question requiring routine techniques: multiplying complex numbers, finding argument and modulus using standard formulas, and calculating distance. All parts are standard FP1 exercises with no novel insight required, making it slightly easier than average A-level difficulty.
Spec4.02a Complex numbers: real/imaginary parts, modulus, argument4.02b Express complex numbers: cartesian and modulus-argument forms4.02e Arithmetic of complex numbers: add, subtract, multiply, divide4.02k Argand diagrams: geometric interpretation

Given that \(z = 1 + \sqrt{3}i\) and that \(\frac{w}{z} = 2 + 2i\), find
  1. \(w\) in the form \(a + ib\), where \(a, b \in \mathbb{R}\), [3]
  2. the argument of \(w\), [2]
  3. the exact value for the modulus of \(w\). [2]
On an Argand diagram, the point \(A\) represents \(z\) and the point \(B\) represents \(w\).
  1. Draw the Argand diagram, showing the points \(A\) and \(B\). [2]
  2. Find the distance \(AB\), giving your answer as a simplified surd. [2]

Given that $z = 1 + \sqrt{3}i$ and that $\frac{w}{z} = 2 + 2i$, find
\begin{enumerate}[label=(\alph*)]
\item $w$ in the form $a + ib$, where $a, b \in \mathbb{R}$, [3]
\item the argument of $w$, [2]
\item the exact value for the modulus of $w$. [2]
\end{enumerate}

On an Argand diagram, the point $A$ represents $z$ and the point $B$ represents $w$.
\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{3}
\item Draw the Argand diagram, showing the points $A$ and $B$. [2]
\item Find the distance $AB$, giving your answer as a simplified surd. [2]
\end{enumerate}

\hfill \mbox{\textit{Edexcel FP1  Q19 [11]}}