Edexcel F1 2020 June — Question 1

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2020
SessionJune
TopicNewton-Raphson method
TypeNewton-Raphson with complex derivative required

1. $$f ( x ) = x ^ { 3 } - \frac { 10 \sqrt { x } - 4 x } { x ^ { 2 } } \quad x > 0$$
  1. Show that the equation \(\mathrm { f } ( x ) = 0\) has a root \(\alpha\) in the interval[1.4,1.5]
  2. Determine \(\mathrm { f } ^ { \prime } ( x )\) .
  3. Using \(x _ { 0 } = 1.4\) as a first approximation to \(\alpha\) ,apply the Newton-Raphson procedure once to \(\mathrm { f } ( x )\) to calculate a second approximation to \(\alpha\) ,giving your answer to 3 decimal places.
    \(f ( x ) = x ^ { 3 } - \frac { 10 \sqrt { x } - 4 x } { x ^ { 2 } } \quad x > 0\)
  4. Show that the equation \(\mathrm { f } ( x ) = 0\) has a root \(\alpha\) in the interval[1.4,1.5]
  5. Determine \(\mathrm { f } ^ { \prime } ( x )\) .