Edexcel F1 2017 June — Question 5

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2017
SessionJune
TopicSign Change & Interval Methods
TypeInterval Bisection with Other Methods

5. $$f ( x ) = 30 + \frac { 7 } { \sqrt { x } } - x ^ { 5 } , \quad x > 0$$ The only real root, \(\alpha\), of the equation \(\mathrm { f } ( x ) = 0\) lies in the interval [2,2.1].
[0pt]
  1. Starting with the interval [2,2.1], use interval bisection twice to find an interval of width 0.025 that contains \(\alpha\).
  2. Taking 2 as a first approximation to \(\alpha\), apply the Newton-Raphson process once to \(\mathrm { f } ( x )\) to find a second approximation to \(\alpha\), giving your answer to 2 decimal places.