AQA Paper 2 2018 June — Question 14 6 marks

Exam BoardAQA
ModulePaper 2 (Paper 2)
Year2018
SessionJune
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVectors 3D & Lines
TypeTriangle and parallelogram problems
DifficultyModerate -0.8 Part (a) is trivial vector subtraction (1 mark). Part (b) requires showing opposite sides are equal vectors (parallelogram) and adjacent sides have different magnitudes (not rhombus) - this is straightforward application of standard vector techniques with no problem-solving insight needed. The 5 marks reflect routine calculations rather than conceptual difficulty.
Spec1.10d Vector operations: addition and scalar multiplication1.10f Distance between points: using position vectors1.10g Problem solving with vectors: in geometry

A quadrilateral has vertices A, B, C and D with position vectors given by $$\overrightarrow{OA} = \begin{pmatrix} 3 \\ 5 \\ 1 \end{pmatrix}, \overrightarrow{OB} = \begin{pmatrix} -1 \\ 2 \\ 7 \end{pmatrix}, \overrightarrow{OC} = \begin{pmatrix} 0 \\ 7 \\ 6 \end{pmatrix} \text{ and } \overrightarrow{OD} = \begin{pmatrix} 4 \\ 10 \\ 0 \end{pmatrix}$$
  1. Write down the vector \(\overrightarrow{AB}\) [1 mark]
  2. Show that ABCD is a parallelogram, but not a rhombus. [5 marks]

Question 14:

AnswerMarks Guidance
14(a)Obtains correct vector AO1.1b
 
3
 
 
6
 

AnswerMarks Guidance
14(b)Obtains one other edge as vector AO1.1a
(cid:4652)(cid:4652)(cid:4652)(cid:4652)(cid:4652)(cid:1318)
(cid:1828)(cid:1829) (cid:3404) (cid:3437) 5 (cid:3441)
(cid:3398)1
1
(cid:4652)(cid:4652)(cid:4652)(cid:4652)(cid:4652)(cid:1318)
(cid:1827)(cid:1830) (cid:3404) (cid:3437) 5 (cid:3441)
(cid:3398)1
(cid:3398)4
(cid:4652)(cid:4652)(cid:4652)(cid:4652)(cid:4652)(cid:1318)
(cid:1830)(cid:1829) (cid:3404) (cid:3437)(cid:3398)3(cid:3441)
6
AB  42 32 62
 61
AD  12 52 12
3 3
(cid:1827)(cid:4652)(cid:4652)(cid:4652)(cid:4652)(cid:1828)(cid:4652)(cid:1318) (cid:3404) (cid:4652)(cid:1830)(cid:4652)(cid:4652)(cid:4652)(cid:1829)(cid:4652)(cid:1318)
ABCD must be a parallelogram
AB AD
ABCD is not a rhombus
Obtains DC correctly
Or
Obtains correctly both BC and AD
Or
AnswerMarks Guidance
Obtains correctly both CB and DAAO1.1b A1
Obtains length of one edge
AnswerMarks Guidance
(or its square)AO1.1a M1
Obtains two correct lengths of
AnswerMarks Guidance
different edgesAO1.1b A1
Completes rigorous argument to
show ABCD is a parallelogram and
AnswerMarks Guidance
not a rhombusAO2.1 R1
Total6
QMarking Instructions AO
Question 14:
--- 14(a) ---
14(a) | Obtains correct vector | AO1.1b | B1 | 4
 
3
 
 
6
 
--- 14(b) ---
14(b) | Obtains one other edge as vector | AO1.1a | M1 | 1
(cid:4652)(cid:4652)(cid:4652)(cid:4652)(cid:4652)(cid:1318)
(cid:1828)(cid:1829) (cid:3404) (cid:3437) 5 (cid:3441)
(cid:3398)1
1
(cid:4652)(cid:4652)(cid:4652)(cid:4652)(cid:4652)(cid:1318)
(cid:1827)(cid:1830) (cid:3404) (cid:3437) 5 (cid:3441)
(cid:3398)1
(cid:3398)4
(cid:4652)(cid:4652)(cid:4652)(cid:4652)(cid:4652)(cid:1318)
(cid:1830)(cid:1829) (cid:3404) (cid:3437)(cid:3398)3(cid:3441)
6
AB  42 32 62
 61
AD  12 52 12
3 3
(cid:1827)(cid:4652)(cid:4652)(cid:4652)(cid:4652)(cid:1828)(cid:4652)(cid:1318) (cid:3404) (cid:4652)(cid:1830)(cid:4652)(cid:4652)(cid:4652)(cid:1829)(cid:4652)(cid:1318)
ABCD must be a parallelogram
AB AD
ABCD is not a rhombus
Obtains DC correctly
Or
Obtains correctly both BC and AD
Or
Obtains correctly both CB and DA | AO1.1b | A1
Obtains length of one edge
(or its square) | AO1.1a | M1
Obtains two correct lengths of
different edges | AO1.1b | A1
Completes rigorous argument to
show ABCD is a parallelogram and
not a rhombus | AO2.1 | R1
Total | 6
Q | Marking Instructions | AO | Marks | Typical Solution
A quadrilateral has vertices A, B, C and D with position vectors given by

$$\overrightarrow{OA} = \begin{pmatrix} 3 \\ 5 \\ 1 \end{pmatrix}, \overrightarrow{OB} = \begin{pmatrix} -1 \\ 2 \\ 7 \end{pmatrix}, \overrightarrow{OC} = \begin{pmatrix} 0 \\ 7 \\ 6 \end{pmatrix} \text{ and } \overrightarrow{OD} = \begin{pmatrix} 4 \\ 10 \\ 0 \end{pmatrix}$$

\begin{enumerate}[label=(\alph*)]
\item Write down the vector $\overrightarrow{AB}$
[1 mark]

\item Show that ABCD is a parallelogram, but not a rhombus.
[5 marks]
\end{enumerate}

\hfill \mbox{\textit{AQA Paper 2 2018 Q14 [6]}}