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Integral ∫(1/2x)dx

  1. Oct 12, 2013 #1
    1. The problem statement, all variables and given/known data


    3. The attempt at a solution

    I factor out (1/2) and i get ∫(1/2x)dx=(1/2)ln|x|+C

    But cant i say that u=2x and dx=du/2 and get ∫(1/2x)dx= (1/2)ln|2x| + C
    (1/2)ln|u| + C
    (1/2)ln|2x| + C

    if i can do this, i get two different answers...

    can i use the last method?
  2. jcsd
  3. Oct 12, 2013 #2


    User Avatar
    Science Advisor

    ln 2x = ln x + ln 2. One of your C constants is equal to the other plus ln 2.

    Both your answers are right...
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