Edexcel Paper 1 2022 June — Question 9 6 marks

Exam BoardEdexcel
ModulePaper 1 (Paper 1)
Year2022
SessionJune
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVector Product and Surfaces
TypeArea of parallelogram using vector product
DifficultyStandard +0.3 This is a straightforward Further Maths vector product question requiring (a) showing two adjacent sides have equal magnitude (simple calculation) and (b) computing area via |a × b|. Both parts are routine applications of standard techniques with no conceptual challenges, making it slightly easier than average even for Further Maths.
Spec1.10c Magnitude and direction: of vectors1.10g Problem solving with vectors: in geometry

9. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{129adfbb-98fa-4e88-b636-7b4d111f3349-20_406_515_246_776} \captionsetup{labelformat=empty} \caption{Figure 3}
\end{figure} Figure 3 shows a sketch of a parallelogram \(P Q R S\).
Given that
  • \(\overrightarrow { P Q } = 2 \mathbf { i } + 3 \mathbf { j } - 4 \mathbf { k }\)
  • \(\overrightarrow { Q R } = 5 \mathbf { i } - 2 \mathbf { k }\)
    1. show that parallelogram \(P Q R S\) is a rhombus.
    2. Find the exact area of the rhombus \(P Q R S\).

Question 9:
Part (a):
AnswerMarks Guidance
AnswerMark Guidance
Attempts both \(\\overrightarrow{PQ}\ =\sqrt{2^2+3^2+(-4)^2}\) and \(\
States \(\\overrightarrow{PQ}\ =\
Total: (2)
Part (b):
AnswerMarks Guidance
AnswerMark Guidance
Attempts BOTH \(\overrightarrow{PR}=\overrightarrow{PQ}+\overrightarrow{QR}=7\mathbf{i}+3\mathbf{j}-6\mathbf{k}\) AND \(\overrightarrow{QS}=-\overrightarrow{PQ}+\overrightarrow{PS}=3\mathbf{i}-3\mathbf{j}+2\mathbf{k}\)M1 For attempting to find both key vectors
Correct \(\overrightarrow{PR}=7\mathbf{i}+3\mathbf{j}-6\mathbf{k}\) and \(\overrightarrow{QS}=3\mathbf{i}-3\mathbf{j}+2\mathbf{k}\)A1 Allow either way around
Correct method for area \(PQRS\), e.g. \(\frac{1}{2}\times\\overrightarrow{PR}\ \times\
\(=\sqrt{517}\)A1
Total: (4)
## Question 9:

### Part (a):
| Answer | Mark | Guidance |
|--------|------|----------|
| Attempts both $\|\overrightarrow{PQ}\|=\sqrt{2^2+3^2+(-4)^2}$ and $\|\overrightarrow{QR}\|=\sqrt{5^2+(-2)^2}$ | M1 | Also accept attempts at $\overrightarrow{PR}\bullet\overrightarrow{QS}$ or $PM^2, MQ^2$ and $PQ^2$ where $M$ is midpoint of $PR$ |
| States $\|\overrightarrow{PQ}\|=\|\overrightarrow{QR}\|=\sqrt{29}$ so $PQRS$ is a rhombus | A1 | Must show calculations and state $PQRS$ is a rhombus; requires reason and conclusion |
| **Total: (2)** | | |

### Part (b):
| Answer | Mark | Guidance |
|--------|------|----------|
| Attempts BOTH $\overrightarrow{PR}=\overrightarrow{PQ}+\overrightarrow{QR}=7\mathbf{i}+3\mathbf{j}-6\mathbf{k}$ AND $\overrightarrow{QS}=-\overrightarrow{PQ}+\overrightarrow{PS}=3\mathbf{i}-3\mathbf{j}+2\mathbf{k}$ | M1 | For attempting to find both key vectors |
| Correct $\overrightarrow{PR}=7\mathbf{i}+3\mathbf{j}-6\mathbf{k}$ and $\overrightarrow{QS}=3\mathbf{i}-3\mathbf{j}+2\mathbf{k}$ | A1 | Allow either way around |
| Correct method for area $PQRS$, e.g. $\frac{1}{2}\times\|\overrightarrow{PR}\|\times\|\overrightarrow{QS}\|$ | dM1 | Dependent on previous M; constructs rigorous method for area |
| $=\sqrt{517}$ | A1 | |
| **Total: (4)** | | |

---
9.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{129adfbb-98fa-4e88-b636-7b4d111f3349-20_406_515_246_776}
\captionsetup{labelformat=empty}
\caption{Figure 3}
\end{center}
\end{figure}

Figure 3 shows a sketch of a parallelogram $P Q R S$.\\
Given that

\begin{itemize}
  \item $\overrightarrow { P Q } = 2 \mathbf { i } + 3 \mathbf { j } - 4 \mathbf { k }$
  \item $\overrightarrow { Q R } = 5 \mathbf { i } - 2 \mathbf { k }$
\begin{enumerate}[label=(\alph*)]
\item show that parallelogram $P Q R S$ is a rhombus.
\item Find the exact area of the rhombus $P Q R S$.
\end{itemize}
\end{enumerate}

\hfill \mbox{\textit{Edexcel Paper 1 2022 Q9 [6]}}