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Homework Help: Help with Differential Equations please!

  1. Mar 11, 2012 #1
    1. The problem statement, all variables and given/known data
    [itex]\frac{dy}{dx}[/itex]=3y f(2)=-1
    [itex]\frac{dy}{dx}[/itex]=e[itex]^{y}[/itex]x when x=-2 y=-ln(3)
    I'm in Calc AB By the way, so please do not try to show me methods that are too advanced.
    2. Relevant equations
    There are no relevant equations?

    3. The attempt at a solution
    My attempt at the first solution is
    You can't have that Natural Log though.. So I 'm stuck.

    My attempt at the second solution is..
    ∫[itex]\frac{dy}{e^{y}}[/itex]=∫x dx
    Last edited: Mar 11, 2012
  2. jcsd
  3. Mar 11, 2012 #2


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    Science Advisor

    Your integration has a common mistake. The integral of 1/y is NOT ln(y), it is ln(|y|).

    (2) is also easy to integrate.
  4. Mar 11, 2012 #3
    Oh man, I'm so used to the absolute value not mattering,that it screwed me up =/ Thank you soooo much.
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