OCR FP1 2011 January — Question 1 7 marks

Exam BoardOCR
ModuleFP1 (Further Pure Mathematics 1)
Year2011
SessionJanuary
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicMatrices
TypeMatrix arithmetic operations
DifficultyEasy -1.8 This is a straightforward matrix arithmetic question testing basic operations: scalar multiplication, matrix addition, and matrix multiplication with compatible dimensions. All three parts are direct applications of definitions with no problem-solving required, making it significantly easier than average A-level questions.
Spec4.03b Matrix operations: addition, multiplication, scalar

\(\mathbf { 1 }\) The matrices \(\mathbf { A } , \mathbf { B }\) and \(\mathbf { C }\) are given by \(\mathbf { A } = \left( \begin{array} { l l } 2 & 5 \end{array} \right) , \mathbf { B } = \left( \begin{array} { l l } 3 & - 1 \end{array} \right)\) and \(\mathbf { C } = \binom { 4 } { 2 }\). Find
  1. \(2 \mathbf { A } + \mathbf { B }\),
  2. \(\mathbf { A C }\),
  3. CB.

Question 1:
Part (i)
AnswerMarks Guidance
AnswerMarks Guidance
\((7 \quad 9)\)B1B1 2 Each element correct; SC (7,9) scores B1
Part (ii)
AnswerMarks Guidance
AnswerMarks Guidance
\((18)\)B1* depB1 2 Obtain correct value; Clearly given as a matrix
Part (iii)
AnswerMarks Guidance
AnswerMarks Guidance
\(\begin{pmatrix} 12 & -4 \\ 6 & -2 \end{pmatrix}\)M1 Obtain \(2 \times 2\) matrix
A1Obtain 2 correct elements
A1 3Obtain other 2 correct elements
## Question 1:

**Part (i)**
| Answer | Marks | Guidance |
|--------|-------|----------|
| $(7 \quad 9)$ | B1B1 **2** | Each element correct; SC (7,9) scores B1 |

**Part (ii)**
| Answer | Marks | Guidance |
|--------|-------|----------|
| $(18)$ | B1* depB1 **2** | Obtain correct value; Clearly given as a matrix |

**Part (iii)**
| Answer | Marks | Guidance |
|--------|-------|----------|
| $\begin{pmatrix} 12 & -4 \\ 6 & -2 \end{pmatrix}$ | M1 | Obtain $2 \times 2$ matrix |
| | A1 | Obtain 2 correct elements |
| | A1 **3** | Obtain other 2 correct elements |

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$\mathbf { 1 }$ The matrices $\mathbf { A } , \mathbf { B }$ and $\mathbf { C }$ are given by $\mathbf { A } = \left( \begin{array} { l l } 2 & 5 \end{array} \right) , \mathbf { B } = \left( \begin{array} { l l } 3 & - 1 \end{array} \right)$ and $\mathbf { C } = \binom { 4 } { 2 }$. Find\\
(i) $2 \mathbf { A } + \mathbf { B }$,\\
(ii) $\mathbf { A C }$,\\
(iii) CB.

\hfill \mbox{\textit{OCR FP1 2011 Q1 [7]}}