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Homework Help: Find integrating factor and solve the equation

  1. Mar 27, 2010 #1
    y dx + x ln x dy = 0 ; x > 0


    my integrating factor is x..


    so.. multiply with DE,


    xy dx + x^2 ln x dy = 0


    let M = xy ; N = x^2 ln x


    dM/dy = x ; dN/dx = x + 2x ln x


    the problem is.. i didn't get the exact equation after multiply the integrating factor.. i've double checked my integrating factor.. but.. still can't get the exact equation...
     
  2. jcsd
  3. Mar 27, 2010 #2

    vela

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    Try dividing by x instead.
     
  4. Mar 27, 2010 #3
    which part?
     
  5. Mar 27, 2010 #4

    vela

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    Instead of multiplying the equation by your integration factor, divide by it instead.
     
  6. Mar 27, 2010 #5
    wow! i got it!! but.. i never divide DE by integrating factor..
    always multiply..
     
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