AQA Further Paper 2 2024 June — Question 14

Exam BoardAQA
ModuleFurther Paper 2 (Further Paper 2)
Year2024
SessionJune
Topic3x3 Matrices

14 The matrix \(\mathbf { M }\) is defined as $$\mathbf { M } = \left[ \begin{array} { c c c } 5 & 2 & 1
6 & 3 & 2 k + 3
2 & 1 & 5 \end{array} \right]$$ where \(k\) is a constant. 14
  1. Given that \(\mathbf { M }\) is a non-singular matrix, find \(\mathbf { M } ^ { - 1 }\) in terms of \(k\)
    14
  2. State any restrictions on the value of \(k\) 14
  3. Using your answer to part (a), show that the solution to the set of simultaneous equations below is independent of the value of \(k\) $$\begin{array} { r l c c } 5 x + 2 y + c & = & 1
    6 x + 3 y + ( 2 k + 3 ) z & = & 4 k + 3
    2 x + y + 5 z & = & 9 \end{array}$$