Verified Solution • 2025–26 Session moderate

QJEEM23Mafaa3: JEE Main 2023 Mathematics - Class 12 JEEM23Mafaa3 Solution: The solution of the differential equation is :

The solution of the differential equation

dydx=−(x2+3y23x2+y2),y(1)=0\frac{d y}{d x}=-\left(\frac{x^2+3 y^2}{3 x^2+y^2}\right), y(1)=0 is :

Multiple Choice Options

  • A log⁡e∣x+y∣+xy(x+y)2=0\log _e|x+y|+\frac{x y}{(x+y)^2}=0
  • B log⁡e∣x+y∣−xy(x+y)2=0\log _e|x+y|-\frac{x y}{(x+y)^2}=0
  • C log⁡e∣x+y∣+2xy(x+y)2=0\log _e|x+y|+\frac{2 x y}{(x+y)^2}=0
  • D log⁡e∣x+y∣−2xy(x+y)2=0\log _e|x+y|-\frac{2 x y}{(x+y)^2}=0

Step-by-Step Verified Solution

y=vxy = vx

v+xdvdx=−(1+3v23+v2)v + x{{dv} \over {dx}} = - \left( {{{1 + 3{v^2}} \over {3 + {v^2}}}} \right)

xdvdx=−(1+3v23+v2+v)x{{dv} \over {dx}} = - \left( {{{1 + 3{v^2}} \over {3 + {v^2}}} + v} \right)

dvdx=−((1+v)33+v2){{dv} \over {dx}} = - \left( {{{{{(1 + v)}^3}} \over {3 + {v^2}}}} \right)

⇒3+v2(1+v)3=−dxx\Rightarrow {{3 + {v^2}} \over {{{(1 + v)}^3}}} = {{ - dx} \over x}

⇒ln⁡∣v+1∣+2v(v+1)2=C−ln⁡∣x∣\Rightarrow \ln |v + 1| + {{2v} \over {{{(v + 1)}^2}}} = C - \ln |x|

x=1,v=0⇒C=0x = 1,v = 0 \Rightarrow C = 0

⇒ln⁡∣x+y∣−ln⁡∣x∣+2xy(x+y)2=−ln⁡∣x∣\Rightarrow \ln |x + y| - \ln |x| + {{2xy} \over {{{(x + y)}^2}}} = - \ln |x|

Related Learning Resources & Exam Preparation