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Thread: Where am i going wrong on this simple integration

  1. #1
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    Where am i going wrong on this simple integration

    $\displaystyle \int\ (4-2x)^3$
    First i factor out a -2
    $\displaystyle -2\int\ (x-2)^3$
    then $\displaystyle u=x-2$
    $\displaystyle du=1$
    $\displaystyle -2\int\ u^3du$
    $\displaystyle \frac{-1}{2}(x-2)^4+C$
    but the book has $\displaystyle -2(x-2)^4+C$
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  2. #2
    Master Of Puppets
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    $\displaystyle
    (4-2x)^3\neq-2\ (x-2)^3
    $
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  3. #3
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    skeeter's Avatar
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    let $\displaystyle u = 4-2x$

    $\displaystyle du = -2 \, dx$
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