Question 1 - A-Level Maths

State the transformation represented by the matrix \(\left( \begin{array} { r r } 1 & 0
0 & - 1 \end{array} \right)\).
Write down the \(2 \times 2\) matrix for rotation through \(90 ^ { \circ }\) anticlockwise about the origin.
Find the \(2 \times 2\) matrix for rotation through \(90 ^ { \circ }\) anticlockwise about the origin, followed by reflection in the \(x\)-axis.