WJEC Further Unit 1 Specimen — Question 7 9 marks

Exam BoardWJEC
ModuleFurther Unit 1 (Further Unit 1)
SessionSpecimen
Marks9
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicComplex Numbers Argand & Loci
TypeComplex transformations and mappings
DifficultyStandard +0.3 This is a standard Further Maths complex numbers locus problem requiring algebraic manipulation. Part (a) involves routine expansion of complex products and equating real/imaginary parts. Part (b) requires substitution and elimination to find a parabola equation—straightforward but multi-step. The techniques are well-practiced in Further Maths courses with no novel insight required.
Spec4.02a Complex numbers: real/imaginary parts, modulus, argument4.02e Arithmetic of complex numbers: add, subtract, multiply, divide

The complex numbers \(z\) and \(w\) are represented, respectively, by points \(P(x, y)\) and \(Q(u,v)\) in Argand diagrams and $$w = z(1 + z)$$
  1. Show that $$v = y(1 + 2x)$$ and find an expression for \(u\) in terms of \(x\) and \(y\). [4]
  2. The point \(P\) moves along the line \(y = x + 1\). Find the Cartesian equation of the locus of \(Q\), giving your answer in the form \(v = au^2 + bu\), where \(a\) and \(b\) are constants whose values are to be determined. [5]

The complex numbers $z$ and $w$ are represented, respectively, by points $P(x, y)$ and $Q(u,v)$ in Argand diagrams and
$$w = z(1 + z)$$

\begin{enumerate}[label=(\alph*)]
\item Show that
$$v = y(1 + 2x)$$
and find an expression for $u$ in terms of $x$ and $y$. [4]

\item The point $P$ moves along the line $y = x + 1$. Find the Cartesian equation of the locus of $Q$, giving your answer in the form $v = au^2 + bu$, where $a$ and $b$ are constants whose values are to be determined. [5]
\end{enumerate}

\hfill \mbox{\textit{WJEC Further Unit 1  Q7 [9]}}