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    if i integrate 36/(2x+1)^4 ,

    i do: 36(1/(2x+1)^4 /2
    = 18 ln(2x+1)4 + c. is this right?

    (Original post by elvss567)
    if i integrate 36/(2x+1)^4 ,

    i do: 36(1/(2x+1)^4 /2
    = 18 ln(2x+1)4 + c. is this right?
    It's not a case of natural logs because the denominator has a power of 4 and not 1 i.e. \int\frac{1}{2x+1}dx becomes a natural log because the denominator is (2x+1)^{1}

    The question is a simple case of integration actually, 36\int\frac{1}{(2x+1)^{4}}dx \Rightarrow 36\int(2x+1)^{-4}dx

    you can change the variable:

    let u = 2x + 1

    du/dx = 2

    dx = du/2

    ∫ 36u-4/2 du

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