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Homework Help: Simple Integral

  1. Sep 1, 2010 #1
    1. The problem statement, all variables and given/known data

    Hello. I have a simple integral here that has been stumping me for the last 30 minutes. It appears that my basic integration skills have gotten very rusty.

    2. Relevant equations


    3. The attempt at a solution
    I am pretty sure a simple substitution will do, but I have yet to find it. I have tried simplifying the expression various ways, integration by parts, and I have also tried a few substitutions. Any ideas?
  2. jcsd
  3. Sep 1, 2010 #2


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    u=1+x^2 will do it.
  4. Sep 1, 2010 #3


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    Gold Member

    The substitution x=tan(u) also works.
  5. Sep 1, 2010 #4
    Thank you Dick and Jgens.


    Let u=1+x^2[tex]\rightarrow[/tex]du=2xdx






    It appears I made a mistake somewhere. I believe my result should be multiplied by 1/2, and I can't find where I left that out.
  6. Sep 1, 2010 #5
    Nevermind. I guess the second part of the problem is incorrect. Mathematica has arrived at the same conclusion as this also. Thanks for all the help.
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