CLAT Sample Paper CLAT Sample Paper-9

  • question_answer
    If\[x=7-4\sqrt{3},\] then \[\sqrt{x}+\frac{1}{\sqrt{x}}\] is equal to

    A)  1                                

    B)  2                    

    C)                     3                   

    D)                     4                    

    Correct Answer: D

    Solution :

    \[x=7-4\sqrt{3}\] \[\therefore \]      \[\sqrt{x}=\sqrt{7-4\sqrt{3}}\] \[=\sqrt{7-2\times 2\times \sqrt{3}}\] \[=\sqrt{4+3-2\times 2\times \sqrt{3}}\] \[=\sqrt{{{(2-\sqrt{3})}^{2}}}=2-\sqrt{3}\] \[\therefore \]      \[\frac{1}{\sqrt{x}}=\frac{1}{2-\sqrt{3}}\] \[=\frac{1}{2-\sqrt{3}}\times \frac{2+\sqrt{3}}{2+\sqrt{3}}\] \[=\frac{2+\sqrt{3}}{4-3}=2+\sqrt{3}\] \[\therefore \]\[\sqrt{x}+\frac{1}{\sqrt{x}}=2-\sqrt{3}+2+\sqrt{3}=4\]


You need to login to perform this action.
You will be redirected in 3 sec spinner