J & K CET Engineering J and K - CET Engineering Solved Paper-2003

  • question_answer
    If \[{{e}^{x}}=y+\sqrt{1+{{y}^{2}}},\] then the value of y is

    A)  \[{{e}^{x}}-{{e}^{-x}}\]

    B)  \[\frac{1}{2}({{e}^{x}}-{{e}^{-x}})\]

    C)  \[{{e}^{x}}+{{e}^{-x}}\]

    D)  None of these

    Correct Answer: B

    Solution :

    Given equation can be rewritten as \[{{e}^{x}}-y=\sqrt{1+{{y}^{2}}}\] On squaring both sides, we get \[{{e}^{2x}}+{{y}^{2}}-2y{{e}^{x}}=1+{{y}^{2}}\] \[\Rightarrow \] \[{{e}^{2x}}-2y{{e}^{x}}=1\] \[\Rightarrow \] \[2y{{e}^{x}}={{e}^{2x}}-1\] \[\Rightarrow \] \[y=\frac{{{e}^{x}}-{{e}^{-x}}}{2}\]


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