Higher November 2021 Paper 3 Q30
30 A sphere has radius \(r\) cm
An approximate value of \(r\) can be found using the iterative formula
\(r_{n+1} = \sqrt{\dfrac{239}{r_n}}\)
The starting value is \(\quad r_1 = 7\)
(a) Work out the values of \(r_2\) and \(r_3\) [2 marks]
(b) Continue the iteration to work out the radius to 1 decimal place. [1 mark]
| Answer | Mark | Comments |
|---|---|---|
| \((r_2 =)\ 5.84(3…)\) | B1 | |
| \((r_3 =)\ 6.39(5…)\) or 6.4(0) | B1ft | ft their 5.84(3…) to 2 dp or better |
Additional guidance
| eg \(r_2 = 6.39(5…)\) and \(r_3 = 6.11(3…)\) | B0B1ft |
| Answer | Mark | Comments |
|---|---|---|
| 6.2 | B1 |
Additional guidance
| 6.20 | B0 |