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Homework Help: Integration by substitution

  1. Mar 8, 2009 #1
    1. The problem statement, all variables and given/known data
    Use substitution to evaluate the integral.
    [tex]\int \frac{4cos(t)}{(2+sin(t))^2}dt [/tex]


    2. Relevant equations
    None, really.


    3. The attempt at a solution
    I'm not sure what to use as u, for the substitution. I've tried [tex](2+sin(t))^2[/tex], as well as other attempts, but I can't seem to find anything.
     
  2. jcsd
  3. Mar 8, 2009 #2
    Sorry, I meant
    [tex]\int \frac{4cos(t)}{(2+sin(t))^2}dt [/tex]
     
  4. Mar 8, 2009 #3

    gabbagabbahey

    User Avatar
    Homework Helper
    Gold Member

    Why not try u=2+sin(t) ?:wink:
     
  5. Mar 9, 2009 #4

    Mark44

    Staff: Mentor

    Always try a simple substitution before you try the more complicated substitutions. If your simple substitution doesn't work, you won't have wasted much time.
     
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