JEE Main & Advanced Mathematics Differentiation Question Bank Derivative at a point Standard Differentiation

  • question_answer
    If \[y=\log \frac{1+\sqrt{x}}{1-\sqrt{x}},\]then \[\frac{dy}{dx}=\]

    A)            \[\frac{\sqrt{x}}{1-x}\]

    B)            \[\frac{1}{\sqrt{x}(1-x)}\]

    C)            \[\frac{\sqrt{x}}{1+x}\]

    D)            \[\frac{1}{\sqrt{x}(1+x)}\]

    Correct Answer: B

    Solution :

               \[t=\frac{5x+1}{10{{x}^{2}}-3},\]            Differentiating w.r.t. x of y, we get            \[\frac{dy}{dx}=\frac{1-\sqrt{x}}{1+\sqrt{x}}\left[ \frac{(1-\sqrt{x})\frac{1}{2\sqrt{x}}+(1+\sqrt{x})\frac{1}{2\sqrt{x}}}{{{(1-\sqrt{x})}^{2}}} \right]\]                \[=\frac{1}{2(1-x)\sqrt{x}}[1-\sqrt{x}+1+\sqrt{x}]=\frac{1}{\sqrt{x}(1-x)}\].


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