Edexcel CP AS 2020 June — Question 1

Exam BoardEdexcel
ModuleCP AS (Core Pure AS)
Year2020
SessionJune
TopicMatrices

  1. A system of three equations is defined by
$$\begin{aligned} k x + 3 y - z & = 3
3 x - y + z & = - k
- 16 x - k y - k z & = k \end{aligned}$$ where \(k\) is a positive constant.
Given that there is no unique solution to all three equations,
  1. show that \(k = 2\) Using \(k = 2\)
  2. determine whether the three equations are consistent, justifying your answer.
  3. Interpret the answer to part (b) geometrically.