Edexcel F1 2015 January — Question 2

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2015
SessionJanuary
TopicNewton-Raphson method
TypeNewton-Raphson with complex derivative required

2. $$f ( x ) = x ^ { 3 } - 3 x ^ { 2 } + \frac { 1 } { 2 \sqrt { x ^ { 5 } } } + 2 , \quad x > 0$$
  1. Show that the equation \(\mathrm { f } ( x ) = 0\) has a root \(\alpha\) in the interval \([ 2,3 ]\).
  2. Taking 3 as a first approximation to \(\alpha\), apply the Newton-Raphson process once to \(\mathrm { f } ( x )\) to find a second approximation to \(\alpha\). Give your answer to 3 decimal places.