CAIE P3 2017 June — Question 6

Exam BoardCAIE
ModuleP3 (Pure Mathematics 3)
Year2017
SessionJune
TopicFixed Point Iteration

6 The equation \(\cot x = 1 - x\) has one root in the interval \(0 < x < \pi\), denoted by \(\alpha\).
  1. Show by calculation that \(\alpha\) is greater than 2.5.
  2. Show that, if a sequence of values in the interval \(0 < x < \pi\) given by the iterative formula \(x _ { n + 1 } = \pi + \tan ^ { - 1 } \left( \frac { 1 } { 1 - x _ { n } } \right)\) converges, then it converges to \(\alpha\).
  3. Use this iterative formula to determine \(\alpha\) correct to 3 decimal places. Give the result of each iteration to 5 decimal places.