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Math Help - Integral

  1. #1
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    Integral

    I understand integrals for the most part...but not sure what to do here.

    Find the particular antiderivative that satisfies the following conditions:
    p'(x)=80/x^3; p(7)=8

    I know that p(x)=-40/x^2, but not sure where to go from there.

    Thanks for your help guys,
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  2. #2
    Math Engineering Student
    Krizalid's Avatar
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    Integrand = antiderivative + constant.

    You forgot to put the constant, after that plug the initial conditions.
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  3. #3
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    So it becomes p(7)=-40/7^2 + C,

    which becomes -40/49 + C

    I still have no idea where the 8 comes into play...i feel like im missing something quite basic here.
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  4. #4
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    p(7)=8. Substitute that in and solve for C.
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  5. #5
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    Plug it into what?

    I feel like a fool.
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  6. #6
    MHF Contributor kalagota's Avatar
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    Quote Originally Posted by calculuslyfrustrated View Post
    Plug it into what?

    I feel like a fool.
    you got p(7) = -\frac{40}{49} + c but from the initial condition, p(7) = 8. so 8 = -\frac{40}{49} + c and solve for c..
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