Edexcel Mathematics June 2018 · Paper 2 · Question 5 · ExamRizz

ExamRizzEdexcel MathematicsMathematics

June 2018 · Paper 2 · Question 5 · 6 marks

5. The equation 2x3 + x2 − 1 = 0 has exactly one real root. (a) Show that, for this equation, the Newton-Raphson formula can be written xxx xxnnn nn+=++ +132 241 62 (3) Using the formula given in part (a) with x1 = 1 (b) find the values of x2 and x3 (2) (c) Explain why, for this question, the Newton-Raphson method cannot be used with x1 = 0 (1) 11

Lesson: Locating Roots by Change of Sign