JEE Main & Advanced Mathematics Definite Integration Question Bank Properties of Definite Integration

  • question_answer
    The value of \[\int_{0}^{1}{{{\tan }^{-1}}\left( \frac{2x-1}{1+x-{{x}^{2}}} \right)}\,dx\] is

    A)                 1             

    B)                 0

    C)                 \[-1\]    

    D)                 None of these

    Correct Answer: B

    Solution :

               \[I=\int_{0}^{1}{{{\tan }^{-1}}}\left( \frac{2x-1}{1+x-{{x}^{2}}} \right)\,dx\]\[=\int_{0}^{1}{{{\tan }^{-1}}}\left( \frac{x+(x-1)}{1-x(x-1)} \right)\,dx\]                    \[I=\int_{0}^{1}{({{\tan }^{-1}}x+{{\tan }^{-1}}(x-1))}\,dx\]                    \[I=\int_{0}^{1}{{{\tan }^{-1}}x\,dx+\int_{0}^{1}{{{\tan }^{-1}}(x-1)\,dx}}\]                    \[I=\int_{0}^{1}{{{\tan }^{-1}}x\,dx+\int_{0}^{1}{{{\tan }^{-1}}(1-x-1)\,dx}}\], {Using \[\int_{0}^{a}{f(x)dx=\int_{0}^{a}{f(a-x)dx}}\]in second integral}                    \[I=\int_{0}^{1}{{{\tan }^{-1}}x\,dx+\int_{0}^{1}{{{\tan }^{-1}}(-x)\,dx}}\]                                 \[I=\int_{0}^{1}{{{\tan }^{-1}}x\,dx-\int_{0}^{1}{{{\tan }^{-1}}x\,dx}=0}\].


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