) The number obtained on rationalising the denominator of \(\frac{1}{\sqrt{7}-2}\) is
A. (√7+2)/3
B. (√7-2)/3
C. (√7+2)/5
D. (√7+2)/45
Answer:A
) The number obtained on rationalising the denominator of \(\frac{1}{\sqrt{7}-2}\) is
A. (√7+2)/3 B. (√7-2)/3 C. (√7+2)/5 D. (√7+2)/45
Explanation: \(\frac{1}{\sqrt{7}-2} = \frac{1}{\sqrt{7}-2}\times \frac{\sqrt{7}+2}{\sqrt{7}+2} = \frac{\sqrt{7}+2}{(\sqrt{7})^{2}-(2)^{2}} = \frac{\sqrt{7}+2}{3}\)