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Help with ODE

  1. Jun 15, 2011 #1
    Can anyone help me solve this ODE:
    ..in other words, find a general solution?

    dy/dx = e^(x+y)

    I use a separation method, but i cant take the natural log of -e^(-y).
    So, help?
  2. jcsd
  3. Jun 16, 2011 #2

    Filip Larsen

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    Gold Member

    Perhaps you can move the minus in front of e-y to the other side of your equation before you apply log.
  4. Jun 16, 2011 #3


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    Science Advisor

    Looks to me like you have forgotten the constant of integration. You should get something like [itex]y= -ln(C- e^x)[/itex] which exists only for [itex]C> e^x[/itex] or [itex]x< ln(C)[/itex]
  5. Jun 20, 2011 #4
    e^(x+y) = e^x * e*y
    e^(-y) dy = e^x dx
    integrate both sides
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