Pre-U Pre-U 9794/1 2014 June — Question 7 4 marks

Exam BoardPre-U
ModulePre-U 9794/1 (Pre-U Mathematics Paper 1)
Year2014
SessionJune
Marks4
TopicNewton-Raphson method
TypeNewton-Raphson with complex derivative required
DifficultyStandard +0.3 This is a straightforward application of the Newton-Raphson formula requiring differentiation of a simple polynomial/rational expression (x^{-2} - 0.119 - 0.018x). While the derivative involves negative powers and the iteration requires careful arithmetic, it's a standard textbook exercise with a given starting value and clear stopping criterion. Slightly above average difficulty only due to the algebraic manipulation needed.
Spec1.09d Newton-Raphson method

7 Taking \(x = 2\) as a first approximation, use the Newton-Raphson process to find a root of the equation \(\frac { 1 } { x ^ { 2 } } - 0.119 - 0.018 x = 0\). Give your answer correct to 3 significant figures.

Obtain any equivalent form of correct derivative \(\frac{-2}{x^3} - 0.018\) — B1
Attempt use of correct formula — M1
Use \(x_0 = 2\) and continue at least as far as \(x_1\) — dep M1
State \(2.47\) — A1 [4]
SR 2.47 may be awarded B1 for any method or no method seen
Obtain any equivalent form of correct derivative $\frac{-2}{x^3} - 0.018$ — B1
Attempt use of correct formula — M1
Use $x_0 = 2$ and continue at least as far as $x_1$ — dep M1
State $2.47$ — A1 **[4]**

SR 2.47 may be awarded B1 for any method or no method seen
7 Taking $x = 2$ as a first approximation, use the Newton-Raphson process to find a root of the equation $\frac { 1 } { x ^ { 2 } } - 0.119 - 0.018 x = 0$. Give your answer correct to 3 significant figures.

\hfill \mbox{\textit{Pre-U Pre-U 9794/1 2014 Q7 [4]}}