1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

First-Order integrating factor of the form f(xy)

  1. Feb 22, 2010 #1
    (Moderator's note: thread moved from "Differential Equations")

    M(x,y) + N(x,y)(dy/dx) = 0

    f'(xy) = G(xy)f(xy) where G(xy) = (Nx - My)/(xM - yN)

    Replace xy with a single variable to obtain a simple 1st order differential equation and find f(xy).

    I got to:

    ln|f| = Integral(G(xy)) by seperating the variables

    But I am unsure how to integrate G(xy) with respect to a single variable.

    Any Suggestions?
    Last edited by a moderator: Feb 26, 2010
  2. jcsd
  3. Feb 25, 2010 #2
    What does f'(xy) denote? Is it [tex]\frac{d}{dx}f(xy)[/tex] or [tex]\frac{d}{d(xy)}f(xy)[/tex]
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook