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Math Help - area between curves w/ integration by parts

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    area between curves w/ integration by parts

    so the two curves are: 12ln(x) and xln(x) I got the bounds to be 1 and 12

    so i got the integral between 1 and 12 of 12ln(x)-xln(x) dx. What do I do after this?
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    That's it, that's the answer
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    Quote Originally Posted by krnbluemonkey View Post
    so the two curves are: 12ln(x) and xln(x) I got the bounds to be 1 and 12

    so i got the integral between 1 and 12 of 12ln(x)-xln(x) dx. What do I do after this?
    12\ln{x} - x\ln{x} = \ln{x}(12-x)

    \int \ln{x}(12-x) \, dx

    let u = \ln{x} and dv = (12-x) \, dx

    you know the rest ...

    \int u \, dv = uv - \int v \, du
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