OCR FP1 — Question 3 7 marks

Exam BoardOCR
ModuleFP1 (Further Pure Mathematics 1)
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicComplex Numbers Arithmetic
TypeDivision plus other arithmetic operations
DifficultyModerate -0.8 This is a straightforward FP1 question testing basic complex number operations: addition, multiplication with conjugates, and finding reciprocals. All three parts are routine calculations requiring only direct application of standard techniques (conjugate definition, multiplication of complex numbers, rationalizing denominators). While FP1 content is more advanced than core A-level, these are foundational exercises within the module with no problem-solving or insight required.
Spec4.02e Arithmetic of complex numbers: add, subtract, multiply, divide

The complex numbers \(2 + 3i\) and \(4 - i\) are denoted by \(z\) and \(w\) respectively. Express each of the following in the form \(x + iy\), showing clearly how you obtain your answers.
  1. \(z + 5w\), [2]
  2. \(z*w\), where \(z*\) is the complex conjugate of \(z\), [3]
  3. \(\frac{1}{w}\). [2]

The complex numbers $2 + 3i$ and $4 - i$ are denoted by $z$ and $w$ respectively. Express each of the following in the form $x + iy$, showing clearly how you obtain your answers.

\begin{enumerate}[label=(\roman*)]
\item $z + 5w$, [2]
\item $z*w$, where $z*$ is the complex conjugate of $z$, [3]
\item $\frac{1}{w}$. [2]
\end{enumerate}

\hfill \mbox{\textit{OCR FP1  Q3 [7]}}