JEE Main & Advanced AIEEE Solved Paper-2004

  • question_answer
    The solution of the differential equation \[ydx+(x+{{x}^{2}}y)dy=0\]is

    A) \[-\frac{1}{xy}=C\]                         

    B) \[-\frac{1}{xy}+\log y=C\]

    C)        \[\frac{1}{xy}+\log y=C\]  

    D)        \[\log y=Cx\]

    Correct Answer: B

    Solution :

    \[ydx+(x+{{x}^{2}}y)dy=0\] \[\Rightarrow \]               \[ydx+xdy=-{{x}^{2}}ydy\] \[\Rightarrow \]               \[\frac{ydx+xdy}{{{x}^{2}}{{y}^{2}}}=-\frac{1}{y}dy\] \[\Rightarrow \]               \[d\left( -\frac{1}{xy} \right)=-\frac{1}{y}dy\] On integrating, we get \[-\frac{1}{xy}=-\log y+C\] \[\Rightarrow \]               \[-\frac{1}{xy}+\log y=C\]


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