SPS SPS FM Pure 2023 September — Question 1 5 marks

Exam BoardSPS
ModuleSPS FM Pure (SPS FM Pure)
Year2023
SessionSeptember
Marks5
TopicMatrices
TypeMatrix inverse calculation
DifficultyModerate -0.8 Part (a) is a routine matrix inversion using the standard 2×2 formula. Part (b) requires knowing that det(A²) = (det A)² and solving a simple quadratic equation. Both parts are straightforward applications of standard Further Maths techniques with no problem-solving insight required, making this easier than average.
Spec4.03h Determinant 2x2: calculation4.03m det(AB) = det(A)*det(B)4.03n Inverse 2x2 matrix

$$\mathbf{A} = \begin{bmatrix} 2 & 3 \\ k & 1 \end{bmatrix}$$
  1. Find \(\mathbf{A}^{-1}\) [2 marks]
  2. The determinant of \(\mathbf{A}^2\) is equal to 4. Find the possible values of \(k\). [3 marks]

$$\mathbf{A} = \begin{bmatrix} 2 & 3 \\ k & 1 \end{bmatrix}$$

\begin{enumerate}[label=(\alph*)]
\item Find $\mathbf{A}^{-1}$ [2 marks]

\item The determinant of $\mathbf{A}^2$ is equal to 4.

Find the possible values of $k$. [3 marks]
\end{enumerate}

\hfill \mbox{\textit{SPS SPS FM Pure 2023 Q1 [5]}}