The given differential equation is:
dxdy+xy=x21
This is a first-order linear differential equation of the form dxdy+P(x)⋅y=Q(x)
Comparing with the standard form:
P(x)=x1
Q(x)=x21
The integrating factor is given by:
I.F.=e∫P(x)dx
I.F.=e∫x1dx
Evaluating the integral:
∫x1dx=ln∣x∣
Therefore:
I.F.=eln∣x∣
I.F.=∣x∣
Since x>0 is given, ∣x∣=x
Therefore, the integrating factor is x.