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Math Help - Integrating factor

  1. #1
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    Integrating factor

    I dont see how to make this into an I.F. format:

    (3x^2y + 2xy + y^3)dx + (x^2 + y^2)dy = 0
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  2. #2
    MHF Contributor FernandoRevilla's Avatar
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    Your equation Pdx+Qdy satisfies:


    \dfrac{1}{Q}\left( \dfrac{\partial P}{\partial y}-\dfrac{\partial Q}{\partial x}\right)=3

    This means that the equation has an integrating factor that depends on x .


    Fernando Revilla
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  3. #3
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    I came up with 3, although I thought that I was looking for an x or some variable as an answer. How does that show that it depends on x. I dont quite understand.
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  4. #4
    MHF Contributor FernandoRevilla's Avatar
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    Quote Originally Posted by dmbocci View Post
    I came up with 3, although I thought that I was looking for an x or some variable as an answer. How does that show that it depends on x. I dont quite understand.

    3=3+0x


    Fernando Revilla
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  5. #5
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    Nope, still dont get it. heh sorry
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  6. #6
    MHF Contributor FernandoRevilla's Avatar
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    Quote Originally Posted by dmbocci View Post
    Nope, still dont get it. heh sorry

    \dfrac{\mu'(x)}{\mu (x)}=3 \Rightarrow\log |\mu(x)|=\int 3\; dx\Rightarrow \ldots


    Fernando Revilla
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