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Math Help - Solve y' + y = e^(3x).

  1. #1
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    Solve y' + y = e^(3x).

    Hi
    this is the question:



    so i set:

    dy/dx + y = e^3x

    but im not sure where to go from here.

    I could also do

    dy + y dx = e^3x dx

    Can someone please explain what i should do?
    Thanks!
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  2. #2
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    Find an integrating factor \displaystyle I = e^{\int 1 ~dx}

    Do you know why?

    What do you get?
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  3. #3
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    right right. So i get e^x as the integrating factor. I think i should know what to do now
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  4. #4
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    Multiply it through both sides of the equation, what do you get?
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