OCR FP1 2008 June — Question 2 7 marks

Exam BoardOCR
ModuleFP1 (Further Pure Mathematics 1)
Year2008
SessionJune
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicComplex Numbers Argand & Loci
TypeSingle locus sketching
DifficultyStandard +0.3 This is a straightforward Further Maths question requiring standard techniques: calculating modulus/argument of a given complex number, then sketching a circle (constant modulus from a point) and a half-line (constant argument from a point). While FP1 content is inherently more advanced than core A-level, these are routine locus types with no problem-solving insight required, making it slightly easier than average overall.
Spec4.02a Complex numbers: real/imaginary parts, modulus, argument4.02k Argand diagrams: geometric interpretation4.02o Loci in Argand diagram: circles, half-lines

2 The complex number \(3 + 4 \mathrm { i }\) is denoted by \(a\).
  1. Find \(| a |\) and \(\arg a\).
  2. Sketch on a single Argand diagram the loci given by
    1. \(| z - a | = | a |\),
    2. \(\arg ( z - 3 ) = \arg a\).

2 The complex number $3 + 4 \mathrm { i }$ is denoted by $a$.\\
(i) Find $| a |$ and $\arg a$.\\
(ii) Sketch on a single Argand diagram the loci given by
\begin{enumerate}[label=(\alph*)]
\item $| z - a | = | a |$,
\item $\arg ( z - 3 ) = \arg a$.
\end{enumerate}

\hfill \mbox{\textit{OCR FP1 2008 Q2 [7]}}