CAIE P2 2005 November — Question 5

Exam BoardCAIE
ModuleP2 (Pure Mathematics 2)
Year2005
SessionNovember
TopicFixed Point Iteration

5
  1. By sketching a suitable pair of graphs, show that there is only one value of \(x\) that is a root of the equation $$\frac { 1 } { x } = \ln x$$
  2. Verify by calculation that this root lies between 1 and 2 .
  3. Show that this root also satisfies the equation $$x = \mathrm { e } ^ { \frac { 1 } { x } }$$
  4. Use the iterative formula $$x _ { n + 1 } = \mathrm { e } ^ { \frac { 1 } { x _ { n } } }$$ with initial value \(x _ { 1 } = 1.8\), to determine this root correct to 2 decimal places. Give the result of each iteration to 4 decimal places.