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Homework Help: Separation Into Differential Equations

  1. Apr 6, 2008 #1
    I would use the entire template except this question is very simple and does not require all of it.

    1. The problem statement, all variables and given/known data
    How do I separate
    [tex]\frac{X''(x)}{X(x)}[/tex]+[tex]\frac{Y''(y)}{Y(y)}[/tex]=[tex]\sigma[/tex]
    into ordinary differential equations when [tex]\sigma[/tex] is a constant.

    Thanks for your help!
     
  2. jcsd
  3. Apr 6, 2008 #2
    You already seem to have seperated the differential equation, because the x-dependence is clearly seperate from the y-dependence.

    On the right hand side you have two terms, one depending on x only the other depending on y only. Their sum should not depend on either x or y but should be constant.

    Can you conclude HOW the x-dependent term must depend on x in order for the sum of this first term and the only(!) y-dependent second term not to depend on x?

    The same for the y-dependence of the second term. Can you figure out HOW it depends on y given the fact that if you add the y-independent first term the result must be y-independent?
     
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