CLAT Sample Paper CLAT Sample Paper-3

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

    A)  \[\frac{10\sqrt{3}}{3}\]

    B)  0

    C)  \[3\sqrt{3}\]

    D)  \[6\sqrt{3}\]

    Correct Answer: B

    Solution :

    \[{{\left( a+\frac{1}{a} \right)}^{2}}=3\] \[\Rightarrow \,\,a+\frac{1}{a}=\sqrt{3}\] Om cubing bnoth sides. \[\therefore \] \[{{\left( a+\frac{1}{a} \right)}^{3}}={{a}^{3}}+\frac{1}{{{a}^{3}}}+3\,\left( a+\frac{1}{a} \right)\] \[\Rightarrow \] \[3\sqrt{3}={{a}^{3}}+\frac{1}{{{a}^{3}}}+3\sqrt{3}\] \[\therefore \] \[{{a}^{3}}+\frac{1}{{{a}^{3}}}=0\]


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