JEE Main & Advanced Mathematics Definite Integration Question Bank Fundamental definite integration, Definite integration by substitution

  • question_answer
    \[\int_{0}^{2/3}{\frac{dx}{4+9{{x}^{2}}}=}\]                                        [MP PET 1997]

    A)                 \[\frac{\pi }{12}\]            

    B)                 \[\frac{\pi }{24}\]

    C)                 \[\frac{\pi }{4}\]              

    D)                 0

    Correct Answer: B

    Solution :

               \[\int_{0}^{2/3}{\frac{dx}{4+9{{x}^{2}}}=\frac{1}{9}\int_{0}^{2/3}{\frac{dx}{{{(2/3)}^{2}}+{{x}^{2}}}}}\]                                 \[=\frac{1}{9}\times \frac{1}{2/3}\left( {{\tan }^{-1}}\frac{x}{2/3} \right)_{0}^{2/3}=\frac{\pi }{4}\times \frac{1}{6}=\frac{\pi }{24}\].


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