When you have a DiffEQ in the form Mdx + Ndy = 0 and you want an exact solution, sometimes you need to multiply by an integration factor p(x,y). The book tells me that the integration factor will either be p =(x^m)(y^n), p = f(x) or p = f(y) and then it gives me the procedure used to solve for all of these cases. Very straightforward.(adsbygoogle = window.adsbygoogle || []).push({});

But how besides insight or guess and check can I decide which type of integration factor to use?

Are there any tricks, rules or patterns?

Let me know if I should clarify further.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Finding an exact solution using an integration factor

**Physics Forums | Science Articles, Homework Help, Discussion**