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X*ln(x) = 1/2x^2*ln(x) - 1/4*x^2 not sure how they got it

  1. Mar 28, 2007 #1
    Hello everyone!

    I'm doing a line integral but i'm confused on the integration method used:

    I got to integral 1 to 3 2*(x^4+xln(x) ); But they then have:
    x^5/5 + 1/2x^2 * ln(x) - 1/4x^2 and i'm not sure how they got the last part, 1/2x^2 * ln(x) - 1/4x^2


    u = x isn't what they did I don't think, and its been awhile so i'm rusty on integration XD
  2. jcsd
  3. Mar 28, 2007 #2


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    The 'hard' part is the integral of x*ln(x). And they just integrated by parts.
  4. Mar 28, 2007 #3
    ahh thank you
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