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Math Help - Integration by parts or by Substitution

  1. #1
    Junior Member
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    Integration by parts or by Substitution

    \int_{1}^{4} (x^2-2) *ln(x) \, dx.
    Which type of integration I should use? and how?
    If I dicede to use integration by substitution:
    u= x^2-2
    du=2xdx
    dx=du/2x
    Then
    \int_{x=1}^{x=4} u *ln(x)*du/2x \, dx=\frac{1}{2}\int_{x=1}^{x=4}\frac{lnx)*du}{x}.
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  2. #2
    Super Member
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    You can use the integration by part.

    \int_{1}^{4}(x^2 - 2)*ln(x)dx = ln(x)( x^3/3 - 2x) - \int( x^3/3 - 2x)*1/x*dx

    now proceed.
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