COMEDK2024Evening ShiftMathematicsDifferential EquationsActual
The general solution of the differential equation x d y d x =y+x ( y x ) is
Options
- A( x y )=C x
- B( x y )=C y
- C( y x )=C x
- D( y x )= C x
Correct answer
C. ( y x )=C x
Step-by-step solution
The given differential equation is x dy dx = y + x ( y x ) . Dividing by x , we get dy dx = y x + ( y x ) . This is a homogeneous differential equation. Let y = vx , then dy dx = v + x dv dx . Substituting these into the equation: v + x dv dx = v + (v) x dv dx = (v) Separating the variables: dv (v) = dx x (v) dv = dx x Integrating both sides: (v) dv = dx x | (v)| = |x| + |C| | (v)| = |Cx| (v) = Cx Substituting v = y x back into the equation: ( y x ) = Cx Answer: ( y x )=C x