problem with first-order nonlinear ordinary differential equation
i have problem to find the solution for : +(x^2+y^2)dy/dx=0)
i have tried the exact equation method :
dx+(x^2+y^2)dy=0)
thus M(x,y)= )
and N(x,y)= )
then deltaM/deltay= 
and deltaN/deltax= 
Since deltaM/deltay does not equal to deltaN/deltax, this imply that the eqution is not exact
thus, finding/searching for integrating factor :
1. 1/N(deltaM/deltay-deltaN/deltax)= /(3x^3y+2xy+y^3)<br />
)
y cannot be eliminated . thus, this is a function of both x and y, not just x
2. 1/M(deltaN/deltax-deltaM/deltay)= /(x^2+y^2))
x cannot be eliminated . thus, this is a function of both x and y, not just y
thus i cannot find the integrating factor in order to solve the DE. where i'm gone wrong? can somebody point it out? i guess may be in algebra...
is there anyway for me to solve the de? please help me.... (Crying)