CLAT Sample Paper CLAT Sample Paper-5

  • question_answer
    If \[{{m}^{2}}-4m+1=0,\] then the value of \[\left( {{m}^{3}}+\frac{1}{{{m}^{3}}} \right)\] is

    A)  48

    B)  52

    C)  64                

    D)  None of these

    Correct Answer: B

    Solution :

    \[\therefore \] \[{{m}^{2}}-4m+1=0\] \[\Rightarrow \] \[{{m}^{2}}+1=4m\] \[\Rightarrow \] \[\frac{{{m}^{2}}+1}{m}=4\] \[\Rightarrow \] \[m+\frac{1}{m}=4\] ?(i) \[\therefore \] \[{{\left( m+\frac{1}{m} \right)}^{3}}={{m}^{3}}+\frac{1}{{{m}^{3}}}+3\,\left( m+\frac{1}{m} \right)=64\] [from Eq. (i)] \[\Rightarrow \] \[{{m}^{3}}+\frac{1}{{{m}^{3}}}=64-12=52\]


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