A2 June 2021 Paper 2 Q1

1 Which of the following matrices is singular?

Circle your answer. [1 mark]

• \[\begin{bmatrix} 1 & 0 \\ 0 & 1 \end{bmatrix}\]
• \[\begin{bmatrix} 1 & 1 \\ 2 & 2 \end{bmatrix}\]
• \[\begin{bmatrix} 0 & 1 \\ 1 & 0 \end{bmatrix}\]
• \[\begin{bmatrix} 1 & -2 \\ 1 & 2 \end{bmatrix}\]