4400 Higher June 2010 Paper 3 Q16
16 Show that \((3 - \sqrt{5})^2 = 14 - 6\sqrt{5}\)
(2)
| Scheme | Marks |
|---|---|
eg \(9 - 3\sqrt{5} - 3\sqrt{5} + \sqrt{5}^2\) \(9 - 2 \times 3\sqrt{5} + \sqrt{5}^2\) | B2 |
| (2) | |
| (2 marks) |
Notes
B2: B1 for \(9 + \sqrt{5}^2\) or \(9 + \sqrt{5}\sqrt{5}\) or \(9 + \sqrt{25}\) or \(3^2 + \sqrt{5}^2\) or \(3^2 + \sqrt{5}\sqrt{5}\) or \(3^2 + \sqrt{25}\)
B1 for \(-3\sqrt{5} - 3\sqrt{5}\) or for \(-2 \times 3\sqrt{5}\)