1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    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!

Need help with this differential equation using separation of variables.

  1. Jan 18, 2010 #1
    1. The problem statement, all variables and given/known data

    The differential equation I have is dy/dx = (xy + 2y - x - 2)/(xy - 3y + x - 3). I need help getting started. Neither the top nor the bottom can be factored, so I don't know what to do next. Can anyone give me a push? All I know is that I need to use separation of variables.
     
  2. jcsd
  3. Jan 18, 2010 #2

    Redbelly98

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    The top and bottom can both be factored ... try again.
     
  4. Jan 18, 2010 #3

    LCKurtz

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Hint: Your numerator can be factored:

    (xy + 2y - x - 2) = y(x + 2) - (x + 2) = (x + 2)(y - 1).

    Similarly in the denominator.
     
  5. Jan 18, 2010 #4
    Oh, of course. Okay, so now I have (x+2)(y-1) on top, and (x-3)(y+1). I have separated those out. Now I have (y+1)/(y-1) dy = (x+2)/(x-3) dx. Is this the correct equation I need to solve?
     
  6. Jan 18, 2010 #5

    Redbelly98

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Looking good so far :smile:
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Need help with this differential equation using separation of variables.
Loading...