JEE Main & Advanced Mathematics Inverse Trigonometric Functions Question Bank Inverse trigonometric functions

  • question_answer
    If \[{{\tan }^{-1}}\frac{a+x}{a}+{{\tan }^{-1}}\frac{a-x}{a}=\frac{\pi }{6}\],then \[{{x}^{2}}\]=

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

    B) \[\sqrt{3}a\]

    C) \[2\sqrt{3}{{a}^{2}}\]

    D) None of these

    Correct Answer: C

    Solution :

      Given equation is \[{{\tan }^{-1}}\frac{a+x}{a}+{{\tan }^{-1}}\frac{a-x}{a}=\frac{\pi }{6}\] \[\Rightarrow \,{{\tan }^{-1\,}}\left( \frac{\frac{a+x}{a}+\frac{a-x}{a}}{1-\frac{a+x}{a}.\,\frac{a-x}{a}} \right)=\frac{\pi }{6}\] \[\Rightarrow \,\,\frac{2{{a}^{2}}}{{{x}^{2}}}=\tan \frac{\pi }{6}=\frac{1}{\sqrt{3}}\,\,\Rightarrow \,\,{{x}^{2}}=2\sqrt{3}{{a}^{2}}\].


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