Easy -1.8 This is a straightforward recognition question worth 1 mark requiring students to identify what a diagonal matrix with entries (1, -1, 1) represents. It tests basic recall of 3D transformation matrices with no calculation or problem-solving required—students simply need to recognize that negating the y-coordinate corresponds to reflection in the plane y=0.
3 Which of the following transformations is represented by the matrix \(\left[ \begin{array} { c c c } 1 & 0 & 0 \\ 0 & - 1 & 0 \\ 0 & 0 & 1 \end{array} \right]\) ?
Tick ( \(\checkmark\) ) one box. [0pt]
[1 mark]
Rotation of \(180 ^ { \circ }\) about the \(x\)-axis □
Reflection in the plane \(x = 0\) □
Rotation of \(180 ^ { \circ }\) about the \(y\)-axis □
Reflection in the plane \(y = 0\) □
3 Which of the following transformations is represented by the matrix $\left[ \begin{array} { c c c } 1 & 0 & 0 \\ 0 & - 1 & 0 \\ 0 & 0 & 1 \end{array} \right]$ ?\\
Tick ( $\checkmark$ ) one box.\\[0pt]
[1 mark]
Rotation of $180 ^ { \circ }$ about the $x$-axis □
Reflection in the plane $x = 0$ □
Rotation of $180 ^ { \circ }$ about the $y$-axis □
Reflection in the plane $y = 0$ □
\hfill \mbox{\textit{AQA Further AS Paper 1 2022 Q3 [1]}}