SPS SPS FM Pure 2021 June — Question 2 3 marks

Exam BoardSPS
ModuleSPS FM Pure (SPS FM Pure)
Year2021
SessionJune
Marks3
TopicFixed Point Iteration

2. The equation \(x ^ { 3 } - 3 x + 1 = 0\) has three real roots.
  1. Show that one of the roots lies between -2 and -1
  2. Taking \(x _ { 1 } = - 2\) as the first approximation to one of the roots, use the Newton-Raphson method to find \(x _ { 2 }\), the second approximation.
    [0pt] [3 marks]
  3. Explain why the Newton-Raphson method fails in the case when the first approximation is \(x _ { 1 } = - 1\)