OCR Further Pure Core 1 2018 March — Question 2

Exam BoardOCR
ModuleFurther Pure Core 1 (Further Pure Core 1)
Year2018
SessionMarch
TopicLinear transformations

2 The matrices \(\mathbf { A }\) and \(\mathbf { B }\) are given by \(\mathbf { A } = \left( \begin{array} { l l } 1 & a
3 & 0 \end{array} \right)\) and \(\mathbf { B } = \left( \begin{array} { l l } 4 & 2
3 & 3 \end{array} \right)\).
  1. Find the value of \(a\) such that \(\mathbf { A B } = \mathbf { B A }\).
  2. Prove by counter example that matrix multiplication for \(2 \times 2\) matrices is not commutative.
  3. A triangle of area 4 square units is transformed by the matrix B. Find the area of the image of the triangle following this transformation.
  4. Find the equations of the invariant lines of the form \(y = m x\) for the transformation represented by matrix \(\mathbf { B }\).