Pre-U Pre-U 9794/1 2016 Specimen — Question 8 4 marks

Exam BoardPre-U
ModulePre-U 9794/1 (Pre-U Mathematics Paper 1)
Year2016
SessionSpecimen
Marks4
TopicNewton-Raphson method
TypeNewton-Raphson with derivative given or simple
DifficultyModerate -0.3 This is a straightforward application of the Newton-Raphson method with a simple cubic function where the derivative is easily found (3x² + 2). The starting value is given, and students just need to iterate the standard formula until convergence to 3 decimal places. This is slightly easier than average as it's a direct procedural application with no complications or interpretation required.
Spec1.09d Newton-Raphson method

8 Given that the equation \(x ^ { 3 } + 2 x - 7 = 0\) has a root between \(x = 1\) and \(x = 2\), use the Newton-Raphson formula with \(x _ { \mathrm { o } } = 1\) to find this root correct to 3 decimal places.

Question 8
- State derivative — B1
- Use of the correct Newton-Raphson formula — M1
- State \(1\) and at least one other correct value \((1.8, 1.59249, 1.56922, 1.56895, 1.56895)\) — A1
- State \(1.569\) — A1
Total: 4 marks
**Question 8**
- State derivative — B1
- Use of the correct Newton-Raphson formula — M1
- State $1$ and at least one other correct value $(1.8, 1.59249, 1.56922, 1.56895, 1.56895)$ — A1
- State $1.569$ — A1

**Total: 4 marks**
8 Given that the equation $x ^ { 3 } + 2 x - 7 = 0$ has a root between $x = 1$ and $x = 2$, use the Newton-Raphson formula with $x _ { \mathrm { o } } = 1$ to find this root correct to 3 decimal places.

\hfill \mbox{\textit{Pre-U Pre-U 9794/1 2016 Q8 [4]}}