Edexcel CP AS 2023 June — Question 3

Exam BoardEdexcel
ModuleCP AS (Core Pure AS)
Year2023
SessionJune
TopicLinear transformations

3. $$\mathbf { A } = \left( \begin{array} { c c c } 1 & 0 & 0
0 & \frac { \sqrt { 3 } } { 2 } & - \frac { 1 } { 2 }
0 & \frac { 1 } { 2 } & \frac { \sqrt { 3 } } { 2 } \end{array} \right)$$
  1. Describe fully the single geometric transformation \(A\) represented by the matrix \(\mathbf { A }\). $$\mathbf { B } = \left( \begin{array} { c c c } 1 & 3 & 0
    \sqrt { 3 } & 0 & 5 \sqrt { 3 }
    1 & 2 & 0 \end{array} \right)$$ The transformation \(B\) is represented by the matrix \(\mathbf { B }\).
    The transformation \(A\) followed by the transformation \(B\) is the transformation \(C\), which is represented by the matrix \(\mathbf { C }\). To determine matrix \(\mathbf { C }\), a student attempts the following matrix multiplication. $$\left( \begin{array} { c c c } 1 & 0 & 0
    0 & \frac { \sqrt { 3 } } { 2 } & - \frac { 1 } { 2 }
    0 & \frac { 1 } { 2 } & \frac { \sqrt { 3 } } { 2 } \end{array} \right) \left( \begin{array} { c c c } 1 & 3 & 0
    \sqrt { 3 } & 0 & 5 \sqrt { 3 }
    1 & 2 & 0 \end{array} \right)$$
  2. State the error made by the student.
  3. Determine the correct matrix \(\mathbf { C }\).