Edexcel F1 2017 January — Question 6

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2017
SessionJanuary
TopicNewton-Raphson method
TypeNewton-Raphson with verification

6. $$f ( x ) = x ^ { 3 } - \frac { 1 } { 2 x } + x ^ { \frac { 3 } { 2 } } , \quad x > 0$$ The root \(\alpha\) of the equation \(\mathrm { f } ( x ) = 0\) lies in the interval [0.6, 0.7].
  1. Taking 0.6 as a first approximation to \(\alpha\), apply the Newton-Raphson process once to \(\mathrm { f } ( x )\) to obtain a second approximation to \(\alpha\). Give your answer to 3 decimal places.
  2. Show that your answer to part (a) is correct to 3 decimal places.