SSC Sample Paper SSC CHSL (10+2) Sample Test Paper-4

  • question_answer
    \[\frac{1}{1-a+{{a}^{2}}}-\frac{1}{1+{{a}^{2}}+a}-\frac{2a}{1+{{a}^{2}}+{{a}^{4}}}=?\]

    A) \[0\]                               

    B) \[-1\]

    C) \[1\]                 

    D)        \[2\]

    Correct Answer: A

    Solution :

    \[\frac{1}{1+{{a}^{2}}-a}-\frac{1}{1+{{a}^{2}}+a}-\frac{2a}{1+{{a}^{4}}+{{a}^{2}}}\] \[=\frac{1+{{a}^{2}}-a(1+{{a}^{2}}-a)}{(1+{{a}^{2}}-a)(1+{{a}^{2}}+a)}-\frac{2a}{1+{{a}^{4}}+{{a}^{2}}}\] \[=\frac{1+{{a}^{2}}+a-1-{{a}^{2}}+a}{{{(1+{{a}^{2}})}^{2}}-{{a}^{2}}}-\frac{2a}{1+{{a}^{4}}+{{a}^{2}}}\] \[=\frac{2a}{1+{{a}^{4}}+2{{a}^{2}}-{{a}^{2}}}-\frac{2a}{1+{{a}^{4}}+{{a}^{2}}}\] \[=\frac{2a}{1+{{a}^{4}}+{{a}^{2}}}-\frac{2a}{1+{{a}^{4}}+{{a}^{2}}}=0\]


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