OCR Further Pure Core 2 2019 June — Question 7 7 marks

Exam BoardOCR
ModuleFurther Pure Core 2 (Further Pure Core 2)
Year2019
SessionJune
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicComplex Numbers Arithmetic
TypeGeometric properties using complex numbers
DifficultyStandard +0.8 This is a Further Maths question requiring geometric understanding of complex numbers, including rotation by 90° (multiplication by ±i) and distance calculations. Part (a) requires finding the side length using modulus, while part (b) demands systematic consideration of two cases (which diagonal) and applying complex number rotations. It goes beyond routine manipulation to require spatial reasoning and multiple solution paths, making it moderately challenging even for Further Maths students.
Spec4.02k Argand diagrams: geometric interpretation4.02l Geometrical effects: conjugate, addition, subtraction

7 In an Argand diagram the points representing the numbers \(2 + 3 \mathrm { i }\) and \(1 - \mathrm { i }\) are two adjacent vertices of a square, \(S\).
  1. Find the area of \(S\).
  2. Find all the possible pairs of numbers represented by the other two vertices of \(S\).

Question 7:
AnswerMarks Guidance
7(a) (2 + 3i) – (1 – i) (= ±(1 + 4i)) soi
17
2 2
AnswerMarks Guidance
1+4i= �1 +4 B1
M1
A1
AnswerMarks
[3]1.1
2.2a
AnswerMarks
1.1Either way round
Can be implied by vector
Or finding the square of their side
AnswerMarks Guidance
Or at 5 – 2i and 6 + 2iA1
[4]3.2a Both clearly paired and in
complex number form for final
AnswerMarks
A1If M1M0A0A0 then add SC1 for
any two correct vertices
Question 7:
7 | (a) | (2 + 3i) – (1 – i) (= ±(1 + 4i)) soi
17
2 2
| 1+4i| = �1 +4 | B1
M1
A1
[3] | 1.1
2.2a
1.1 | Either way round
Can be implied by vector
Or finding the square of their side
Or at 5 – 2i and 6 + 2i | A1
[4] | 3.2a | Both clearly paired and in
complex number form for final
A1 | If M1M0A0A0 then add SC1 for
any two correct vertices
7 In an Argand diagram the points representing the numbers $2 + 3 \mathrm { i }$ and $1 - \mathrm { i }$ are two adjacent vertices of a square, $S$.
\begin{enumerate}[label=(\alph*)]
\item Find the area of $S$.
\item Find all the possible pairs of numbers represented by the other two vertices of $S$.
\end{enumerate}

\hfill \mbox{\textit{OCR Further Pure Core 2 2019 Q7 [7]}}