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

  • question_answer
    \[\int_{{}}^{{}}{\frac{{{x}^{e-1}}+{{e}^{x-1}}}{{{x}^{e}}+{{e}^{x}}}dx=}\]

    A)            \[\log ({{x}^{e}}+{{e}^{x}})+c\]

    B)            \[e\log ({{x}^{e}}+{{e}^{x}})+c\]

    C)            \[\frac{1}{e}\log ({{x}^{e}}+{{e}^{x}})+c\]

    D)            None of these

    Correct Answer: C

    Solution :

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


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