JEE Main & Advanced Mathematics Differential Equations Question Bank Variable Separable type differential equations

  • question_answer
    The general solution of the differential equation \[\log \left( \frac{dy}{dx} \right)=x+y\] is        [MP PET 1994; 1995; DSSE 1984]

    A)                 \[{{e}^{x}}+{{e}^{y}}=c\]          

    B)                 \[{{e}^{x}}+{{e}^{-y}}=c\]

    C)                 \[{{e}^{-x}}+{{e}^{y}}=c\]                         

    D)                 \[{{e}^{-x}}+{{e}^{-y}}=c\]

    Correct Answer: B

    Solution :

                       \[\log \left( \frac{dy}{dx} \right)=x+y\] Þ \[{{e}^{x+y}}=\frac{dy}{dx}\]Þ\[{{e}^{x}}{{e}^{y}}=\frac{dy}{dx}\]                                 Þ \[\int_{{}}^{{}}{{{e}^{x}}dx}=\int_{{}}^{{}}{\frac{dy}{{{e}^{y}}}}\] Þ \[{{e}^{x}}=-{{e}^{-y}}+c\]Þ \[{{e}^{x}}+{{e}^{-y}}=c\].


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