A) 4
B) 6
C) 3
D) 2
Correct Answer: A
Solution :
We have \[x=\sqrt{7+4\sqrt{3}}\] \ \[\frac{1}{x}=\frac{1}{\sqrt{7+4\sqrt{3}}}=\frac{\sqrt{7-4\sqrt{3}}}{\sqrt{7+4\sqrt{3}}.\sqrt{7-4\sqrt{3}}}\] \[=\sqrt{7-4\sqrt{3}}\] \\[x+\frac{1}{x}=\sqrt{7+4\sqrt{3}}+\sqrt{7-4\sqrt{3}}\] \[=(\sqrt{3}+2)+(2-\sqrt{3})=4\].You need to login to perform this action.
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