2. Sample Papers
  3. SSC

SSC Sample Paper SSC CHSL (10+2) Sample Test Paper-9

  • question_answer
    If \[a=2+\sqrt{3}\] , then the value of  \[\left( {{a}^{2}}+\frac{1}{{{a}^{2}}} \right)\]is

    A) 12                                

    B) 14

    C) 16                                

    D) 10

    Correct Answer: B

    Solution :

    \[a=2+\sqrt{3}\] \[\frac{1}{a}=\frac{1}{2+\sqrt{3}}=\frac{1}{(2+\sqrt{3})}\times \frac{2-\sqrt{3}}{(2-\sqrt{3})}\]             \[=\frac{2-\sqrt{3}}{4-3}=2-\sqrt{3}\] \[\therefore \]\[{{a}^{2}}+\frac{1}{{{a}^{2}}}={{\left( a+\frac{1}{a} \right)}^{2}}-2\] \[={{(2+\sqrt{3}+2-\sqrt{3})}^{2}}-2\] \[=16-2=14\]


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