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

  • question_answer
    If \[y=\frac{{{e}^{x}}+{{e}^{-x}}}{{{e}^{x}}-{{e}^{-x}}}\] then \[\frac{dy}{dx}\] is equal to    [Karnataka CET 2005]

    A)            \[\sec {{\text{h}}^{2}}x\]

    B)            \[\text{cosec}{{\text{h}}^{2}}x\]

    C)            \[-\sec \,{{\text{h}}^{2}}x\]

    D)            \[-\text{cosec}{{\text{h}}^{2}}x\]

    Correct Answer: D

    Solution :

               \[y=\frac{{{e}^{x}}+{{e}^{-x}}}{{{e}^{x}}-{{e}^{-x}}}=\frac{\frac{{{e}^{x}}+{{e}^{-x}}}{2}}{\frac{{{e}^{x}}-{{e}^{-x}}}{2}}=\frac{\cosh x}{\sinh x}=\coth \,x\]            \[\frac{dy}{dx}=-\text{cosec}{{\text{h}}^{\text{2}}}x\].


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