JEE Main & Advanced Mathematics Indefinite Integrals Question Bank Integration by Substitution

  • question_answer
    \[\int_{{}}^{{}}{\frac{1}{x{{(\log x)}^{2}}}}\ dx=\]

    A)            \[\frac{1}{\log x}+c\]

    B)            \[-\frac{1}{\log x}+c\]

    C)            \[\log \log x+c\]

    D)            \[-\log \log x+c\]

    Correct Answer: B

    Solution :

                       Put \[\log x=t\Rightarrow \frac{1}{x}\,dx=dt,\] then            \[\int_{{}}^{{}}{\frac{1}{x{{(\log x)}^{2}}}\,dx}=\int_{{}}^{{}}{\frac{1}{{{t}^{2}}}\,dt}=-\frac{1}{t}+c=-\frac{1}{\log x}+c.\]


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