A) \[5\sqrt{2}\]
B) \[2\sqrt{5}\]
C) \[4\sqrt{2}\]
D) \[4\sqrt{5}\]
Correct Answer: B
Solution :
\[x-\frac{1}{x}=4\] (Given) \[\therefore \] \[{{\left( x+\frac{1}{x} \right)}^{2}}={{\left( x-\frac{1}{x} \right)}^{2}}+4={{(4)}^{2}}+4=20\] \[\Rightarrow \] \[x+\frac{1}{x}=\sqrt{20}=2\sqrt{5}\]You need to login to perform this action.
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