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Homework Help: Integration by parts help.

  1. Oct 24, 2007 #1
    [SOLVED] Integration by parts help.

    1. The problem statement, all variables and given/known data
    I'm working on ym Math assignment, and we are currently doing Integration by parts. I haven't had too much trouble except with the last 3. Ill only post the first of those 3 for now.
    I need to find [tex]\int[/tex]arctan(1/x)dx





    2. Relevant equations



    3. The attempt at a solution
    I picked u to be arctan(1/x) and dv to be 1.

    so far this is what i have:
    =xarctan(1/x) - [tex]\int[/tex] (-x)/(x[tex]^{2}[/tex] +1) dx

    Have I done it right so far? Any tips on how to procede?
     
  2. jcsd
  3. Oct 24, 2007 #2
    use a u=subt for your integral and you're done!
     
  4. Oct 24, 2007 #3
    I got xarctan(1/x) + 1/2ln(x^2 +1) + c as my final answer.

    Does that look right?
     
  5. Oct 24, 2007 #4
    that's what i got :-]
     
  6. Oct 24, 2007 #5
    Alright thanks a lot.

    Edit Nevermind found what i was doing wrong
     
    Last edited: Oct 24, 2007
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