Edexcel F1 2016 January — Question 2

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2016
SessionJanuary
TopicNewton-Raphson method
TypeNewton-Raphson with complex derivative required

2. $$\mathrm { f } ( x ) = x ^ { 2 } - \frac { 3 } { \sqrt { x } } - \frac { 4 } { 3 x ^ { 2 } } , \quad x > 0$$
  1. Show that the equation \(\mathrm { f } ( x ) = 0\) has a root \(\alpha\) in the interval [1.6,1.7]
  2. Taking 1.6 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.