Rationalise the denominator
\[ \frac{1}{\sqrt{7} + 2} \]
Solution:
\[ \frac{1}{\sqrt{7} + 2} \times \frac{\sqrt{7} – 2}{\sqrt{7} – 2} \]
\[ = \frac{\sqrt{7} – 2}{7 – 4} \]
\[ = \frac{\sqrt{7} – 2}{3} \]
\[ \frac{1}{\sqrt{7} + 2} \]
\[ \frac{1}{\sqrt{7} + 2} \times \frac{\sqrt{7} – 2}{\sqrt{7} – 2} \]
\[ = \frac{\sqrt{7} – 2}{7 – 4} \]
\[ = \frac{\sqrt{7} – 2}{3} \]