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Homework Help: Partial differential equation

  1. Oct 26, 2005 #1
    Hi does anyone know how to solve this partial differential equation. My brain appears to be burping (and strangely my past notes don't seem to have any similar equation in):confused:
    [tex]\frac{\partial{\psi}}{\partial{x}} = k(x+y)[/tex]
    Anyone know any good tutorials or webpages for these sorts of equation? I'm a bit rusty with them
     
  2. jcsd
  3. Oct 26, 2005 #2
  4. Oct 26, 2005 #3

    HallsofIvy

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    [tex]\frac{\partial{\psi}}{\partial{x}} = k(x+y)[/tex]

    Since x and y are independent, all you can do is integrate, with respect to x, treating y as a constant:
    [tex]\psi(x,y)= \frac{k}{2}x^2+ yx+ f(y)[/tex]
    Since the partial derivative wrt x is taken treating y as a constant, f(y) could be any function of y alone- its derivative will be 0.
     
  5. Oct 26, 2005 #4
    I tried that but didn't get the right answer, I'll give it another shot.

    Although isn't the second term kyx as it too is multiplied by k? Or am I being incredibly dense, it does happen a lot
     
  6. Oct 27, 2005 #5
    Turn out the reason I was going wrong wasn't my method, I lost a minus in the calculation (slippery little blighters):rolleyes:

    Thanks for the help anyway
     
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