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Homework Help: TWO 2nd order coupled DEs

  1. Feb 15, 2010 #1
    1. The problem statement.
    Two 2nd order ODEs are given as :
    x''-2xy''+x^2 y' = 0
    x"+y"+xy'+yx'=0
    write a code to solve them numerically using RK4 in matlab.


    3. The attempt at a solution

    I have some idea of starting this kind of problem. That is, I first need to convert them into Four 1st order ODEs. I began this by:

    let p=x' and q=y'
    So, p'=x" and q'=y"

    put these in original eqn, I got

    p'-2xq'+x^2 q = 0
    p'+q'+xp+yq = 0

    What should I do now? Is my approach correct? I didn't get Four Eqns as I expected!
    PLEASE HELP
     
  2. jcsd
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