Edexcel FP1 — Question 1 5 marks

Exam BoardEdexcel
ModuleFP1 (Further Pure Mathematics 1)
Marks5
PaperDownload PDF ↗
TopicComplex Numbers Arithmetic
TypeDivision plus modulus/argument
DifficultyModerate -0.3 This is a straightforward Further Maths question testing basic complex number operations: (a) requires algebraic manipulation to find w by multiplying both sides by w and rationalizing, (b) is a direct application of the arctan formula for argument. Both parts are routine calculations with no conceptual challenges, though being FP1 content places it slightly above average C3 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, divide

Given that \(z = 22 + 4i\) and \(\frac{z}{w} = 6 - 8i\), find
  1. \(w\) in the form \(a + bi\), where \(a\) and \(b\) are real, [3]
  2. the argument of \(z\), in radians to 2 decimal places. [2]

Given that $z = 22 + 4i$ and $\frac{z}{w} = 6 - 8i$, find
\begin{enumerate}[label=(\alph*)]
\item $w$ in the form $a + bi$, where $a$ and $b$ are real, [3]
\item the argument of $z$, in radians to 2 decimal places. [2]
\end{enumerate}

\hfill \mbox{\textit{Edexcel FP1  Q1 [5]}}