SSC Sample Paper SSC CHSL (10+2) Sample Test Paper-1

  • question_answer
    If\[{{x}^{2}}+\frac{1}{{{x}^{2}}}=66\], then the value of\[\frac{{{x}^{2}}-1+2x}{x}=?\]

    A)  \[\pm 8\]                                  

    B) \[10,\,\,-6\]  

    C) \[6,\,\,-10\]                    

    D)  \[\pm 4\]

    Correct Answer: B

    Solution :

    \[{{x}^{2}}+\frac{1}{{{x}^{2}}}=66\] \[\Rightarrow \]   \[{{\left( x-\frac{1}{x} \right)}^{2}}+2=66\] \[\Rightarrow \]   \[{{\left( x-\frac{1}{x} \right)}^{2}}=66-2=64\] \[\Rightarrow \]   \[x-\frac{1}{x}=\pm 8\] \[\therefore \]Expression\[=\frac{{{x}^{2}}-1+2x}{x}\]             \[\frac{{{x}^{2}}}{x}-\frac{1}{x}+2=x-\frac{1}{x}+2\] Putting the value of\[x-\frac{1}{x}\]             \[=8+2\]or\[-8+2=10\,\,\text{or}\,\,-6\]


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