Higher June 2018 Paper 3 Q23
23 A sequence of numbers is formed by the iterative process
\[u_{n+1} = \frac{3}{u_n + 1}, \qquad u_1 = 4\]Work out the values of \(u_2\) and \(u_3\) [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(u_2 = 0.6\) or \(\dfrac{3}{5}\) \(u_3 = 1.875\) or \(\dfrac{15}{8}\) | B2 | oe B1 for 1 correct or for \(u_2\) incorrect but their value of \(u_3\) correctly follows through rounded or truncated to 4 dp |
Additional guidance
| \(u_1 = 0.6\), \(\;u_2 = 1.875\), \(\;u_3 = 1.0434\)… or \(u_3 = 1.0435\) | B1 |