SPS SPS FM 2022 February — Question 1 4 marks

Exam BoardSPS
ModuleSPS FM (SPS FM)
Year2022
SessionFebruary
Marks4
TopicMatrices
TypeMatrix arithmetic operations
DifficultyEasy -1.3 This is a straightforward matrix arithmetic question requiring only basic operations (scalar multiplication and matrix addition/subtraction) with 2×2 matrices. Both parts are routine calculations with no problem-solving or conceptual depth—part (i) is direct computation, and part (ii) simply verifies an identity by subtraction. This is easier than average A-level content, similar to early exercises in a Further Maths matrices chapter.
Spec4.03b Matrix operations: addition, multiplication, scalar

The matrices \(\mathbf{A}\) and \(\mathbf{B}\) are given by \(\mathbf{A} = \begin{pmatrix} 4 & 1 \\ 0 & 2 \end{pmatrix}\) and \(\mathbf{B} = \begin{pmatrix} 1 & 1 \\ 0 & -1 \end{pmatrix}\).
  1. Find \(\mathbf{A} + 3\mathbf{B}\). [2]
  2. Show that \(\mathbf{A} - \mathbf{B} = k\mathbf{I}\), where \(\mathbf{I}\) is the identity matrix and \(k\) is a constant whose value should be stated. [2]

The matrices $\mathbf{A}$ and $\mathbf{B}$ are given by $\mathbf{A} = \begin{pmatrix} 4 & 1 \\ 0 & 2 \end{pmatrix}$ and $\mathbf{B} = \begin{pmatrix} 1 & 1 \\ 0 & -1 \end{pmatrix}$.

\begin{enumerate}[label=(\roman*)]
\item Find $\mathbf{A} + 3\mathbf{B}$. [2]
\item Show that $\mathbf{A} - \mathbf{B} = k\mathbf{I}$, where $\mathbf{I}$ is the identity matrix and $k$ is a constant whose value should be stated. [2]
\end{enumerate}

\hfill \mbox{\textit{SPS SPS FM 2022 Q1 [4]}}