JEE Main & Advanced Sample Paper JEE Main - Mock Test - 16

  • question_answer
    The solution for x of the equation\[\int\limits_{\sqrt{2}}^{x}{\frac{dt}{t\sqrt{{{t}^{2}}-1}}}=\frac{\pi }{2}\]is

    A) \[\frac{\sqrt{3}}{2}\]                 

    B) \[2\sqrt{2}\]

    C) \[-\sqrt{2}\]                   

    D) \[\pi \]

    Correct Answer: C

    Solution :

    [c] : We have, \[\int\limits_{\sqrt{2}}^{x}{\frac{dt}{t\sqrt{{{t}^{2}}-1}}}=\frac{\pi }{2}\] \[\Rightarrow \]\[\left[ {{\sec }^{-1}}t \right]_{\sqrt{2}}^{x}=\frac{\pi }{2}\] \[\Rightarrow \]\[{{\sec }^{-1}}x-{{\sec }^{-1}}\sqrt{2}=\frac{\pi }{2}\Rightarrow {{\sec }^{-1}}x=\frac{\pi }{2}+\frac{\pi }{4}=\frac{3\pi }{4}\] \[\Rightarrow \]\[x=-\sqrt{2}\].


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