OCR MEI Further Pure Core 2024 June — Question 5 6 marks

Exam BoardOCR MEI
ModuleFurther Pure Core (Further Pure Core)
Year2024
SessionJune
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVectors: Cross Product & Distances
TypeAngle between vectors using scalar product
DifficultyStandard +0.3 This is a straightforward Further Maths question testing standard cross product calculation and the relationship |u×v| = |u||v|sinθ. Part (a) requires computing a cross product and equating components (routine algebra), while part (b) applies a standard formula. The question is slightly above average difficulty due to being Further Maths content, but it's a textbook application with no novel insight required.
Spec4.04c Scalar product: calculate and use for angles4.04g Vector product: a x b perpendicular vector

5
  1. Given that \(\mathbf { u } = \left( \begin{array} { r } - 2 \\ 1 \\ 2 \end{array} \right) , \mathbf { v } = \left( \begin{array} { l } a \\ 0 \\ 1 \end{array} \right)\) and \(\mathbf { u } \times \mathbf { v } = \left( \begin{array} { l } 1 \\ b \\ 3 \end{array} \right)\), find \(a\) and \(b\).
  2. Using \(\mathbf { u } \times \mathbf { v }\), determine the angle between the vectors \(\mathbf { u }\) and \(\mathbf { v }\), given that this angle is acute.

Question 5:
AnswerMarks Guidance
5(a)  1 
u  v = 2 + 2 a
− a
2 + 2a = b, −a = 3
AnswerMarks
a = −3, b = −4B1
M1
A1
AnswerMarks
[3]1.1
1.1
AnswerMarks
1.1oe
soi by correct equations
Both equations ft their 𝐮×𝐯
www
AnswerMarks Guidance
5(b) u  v
s in  =
u v
26
=
9 10
AnswerMarks
 = 32.51…M1
A1FT
A1
AnswerMarks
[3]3.1a
1.1
AnswerMarks
1.1s i n  u  v = u v must be used with their 𝐮 and 𝐯
soi by correct expression for their sin𝜃. Formula alone is
M0.
ft their a and b, need not be simplified
33 or 0.57 rad or better
Question 5:
5 | (a) |  1 
u  v = 2 + 2 a
− a
2 + 2a = b, −a = 3
a = −3, b = −4 | B1
M1
A1
[3] | 1.1
1.1
1.1 | oe
soi by correct equations
Both equations ft their 𝐮×𝐯
www
5 | (b) | u  v
s in  =
u v
26
=
9 10
 = 32.51… | M1
A1FT
A1
[3] | 3.1a
1.1
1.1 | s i n  u  v = u v must be used with their 𝐮 and 𝐯
soi by correct expression for their sin𝜃. Formula alone is
M0.
ft their a and b, need not be simplified
33 or 0.57 rad or better
5
\begin{enumerate}[label=(\alph*)]
\item Given that $\mathbf { u } = \left( \begin{array} { r } - 2 \\ 1 \\ 2 \end{array} \right) , \mathbf { v } = \left( \begin{array} { l } a \\ 0 \\ 1 \end{array} \right)$ and $\mathbf { u } \times \mathbf { v } = \left( \begin{array} { l } 1 \\ b \\ 3 \end{array} \right)$, find $a$ and $b$.
\item Using $\mathbf { u } \times \mathbf { v }$, determine the angle between the vectors $\mathbf { u }$ and $\mathbf { v }$, given that this angle is acute.
\end{enumerate}

\hfill \mbox{\textit{OCR MEI Further Pure Core 2024 Q5 [6]}}