Edexcel FP1 2009 June — Question 1 8 marks

Exam BoardEdexcel
ModuleFP1 (Further Pure Mathematics 1)
Year2009
SessionJune
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicComplex Numbers Argand & Loci
TypeComplex arithmetic operations
DifficultyModerate -0.8 This is a straightforward FP1 question testing basic complex number operations: plotting points, finding modulus (using Pythagoras), finding argument (using arctan), and division (multiplying by conjugate). All are standard procedures with no problem-solving required, making it easier than average even for Further Maths.
Spec4.02c Complex notation: z, z*, Re(z), Im(z), |z|, arg(z)4.02e Arithmetic of complex numbers: add, subtract, multiply, divide4.02k Argand diagrams: geometric interpretation

  1. The complex numbers \(z _ { 1 }\) and \(z _ { 2 }\) are given by
$$z _ { 1 } = 2 - i \quad \text { and } \quad z _ { 2 } = - 8 + 9 i$$
  1. Show \(z _ { 1 }\) and \(z _ { 2 }\) on a single Argand diagram. Find, showing your working,
  2. the value of \(\left| z _ { 1 } \right|\),
  3. the value of \(\arg z _ { 1 }\), giving your answer in radians to 2 decimal places,
  4. \(\frac { Z _ { 2 } } { Z _ { 1 } }\) in the form \(a + b \mathrm { i }\), where \(a\) and \(b\) are real.

\begin{enumerate}
  \item The complex numbers $z _ { 1 }$ and $z _ { 2 }$ are given by
\end{enumerate}

$$z _ { 1 } = 2 - i \quad \text { and } \quad z _ { 2 } = - 8 + 9 i$$

(a) Show $z _ { 1 }$ and $z _ { 2 }$ on a single Argand diagram.

Find, showing your working,\\
(b) the value of $\left| z _ { 1 } \right|$,\\
(c) the value of $\arg z _ { 1 }$, giving your answer in radians to 2 decimal places,\\
(d) $\frac { Z _ { 2 } } { Z _ { 1 } }$ in the form $a + b \mathrm { i }$, where $a$ and $b$ are real.\\

\hfill \mbox{\textit{Edexcel FP1 2009 Q1 [8]}}