Specimen 2020 Paper 1 Q14
14 Rationalise and simplify \(\quad \dfrac{\sqrt{3} - 7}{\sqrt{3} + 1}\)
Give your answer in the form \(\quad a + b\sqrt{3} \quad\) where \(a\) and \(b\) are integers. [4 marks]
| Answer | Mark | Comments |
|---|---|---|
| Multiplies numerator and denominator by \(\sqrt{3} - 1\) | M1 | |
| (denominator =) 2 | A1 | |
| (numerator =) \(3 - \sqrt{3} - 7\sqrt{3} + 7\) or \(10 - 8\sqrt{3}\) | M1dep | |
| \(5 - 4\sqrt{3}\) | A1 |