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Homework Help: Help manipulating integral to use arctan or trig-sub methods

  1. Dec 7, 2011 #1
    1. The problem statement, all variables and given/known data
    ∫1/(x2+4)2


    2. Relevant equations
    ∫dx/(x2+a2)=(1/a)arctan(x/a)+c


    3. The attempt at a solution
    This looks like an arctan integral or a trig substitution, but in its current form neither would work without manipulation. I'm mainly looking for how to manipulate it to use one of these methods

    Thanks!
     
    Last edited: Dec 7, 2011
  2. jcsd
  3. Dec 8, 2011 #2

    Mark44

    Staff: Mentor

    Trig substitution is the way to go here. Do you know the substitution to use?
     
  4. Dec 8, 2011 #3
    I'm only giving this one hint then it's up to you to complete the rest.

    square root (a^2 + u^2)

    u = a*tan(theta)
     
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