AQA Paper 2 Specimen — Question 5 8 marks

Exam BoardAQA
ModulePaper 2 (Paper 2)
SessionSpecimen
Marks8
TopicSign Change & Interval Methods
TypeSign Change with Function Evaluation

5
20
40
200 3 A curve is defined by the parametric equations $$x = t ^ { 3 } + 2 , \quad y = t ^ { 2 } - 1$$ 3
  1. Find the gradient of the curve at the point where \(t = - 2\)
    [0pt] [4 marks]
    3
  2. Find a Cartesian equation of the curve.
    4 The equation \(x ^ { 3 } - 3 x + 1 = 0\) has three real roots. 4
  3. Show that one of the roots lies between - 2 and - 1
    4
  4. 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]
    4
  5. Explain why the Newton-Raphson method fails in the case when the first approximation is \(x _ { 1 } = - 1\)
    [0pt] [1 mark]