Question:
The rationalisation factor of $\frac{1}{2 \sqrt{3}-\sqrt{5}}$ is
(a) $\sqrt{5}-2 \sqrt{3}$
(b) $\sqrt{3}+2 \sqrt{5}$
(c) $(\sqrt{3}+\sqrt{5})$
(d) $\sqrt{12}+\sqrt{5}$
Solution:
Rationalisation factor of $\frac{1}{2 \sqrt{3}-\sqrt{5}}$ will be $2 \sqrt{3}+\sqrt{5}=\sqrt{4 \times 3}+\sqrt{5}=\sqrt{12}+\sqrt{5}$.
Hence, the correct answer is option (d).