CAIE P3 2023 June — Question 6

Exam BoardCAIE
ModuleP3 (Pure Mathematics 3)
Year2023
SessionJune
TopicFixed Point Iteration

6 The equation \(\cot \frac { 1 } { 2 } x = 3 x\) has one root in the interval \(0 < x < \pi\), denoted by \(\alpha\).
  1. Show by calculation that \(\alpha\) lies between 0.5 and 1 .
  2. Show that, if a sequence of positive values given by the iterative formula $$x _ { n + 1 } = \frac { 1 } { 3 } \left( x _ { n } + 4 \tan ^ { - 1 } \left( \frac { 1 } { 3 x _ { n } } \right) \right)$$ converges, then it converges to \(\alpha\).
  3. Use this iterative formula to calculate \(\alpha\) correct to 2 decimal places. Give the result of each iteration to 4 decimal places.