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Homework Help: Trig substitution (integration)

  1. Feb 18, 2007 #1
    1. The problem statement, all variables and given/known data
    30x75o8.gif

    2. Relevant equations

    3. The attempt at a solution
    I'm not asking for someone to do the question for me but I was just wondering what I'm supposed to sub in. Do I put in 2pyuz2w.gif as if it was (x^2-9)^(1/2) or do I have to do something differently if there is a constant in front of the x^2? Thanks for any help.
     
  2. jcsd
  3. Feb 18, 2007 #2
    You are correct, secant is the correct trig function to use in this case.
    However the coefficient is incomplete, you need to divide out the 4 as well.
     
  4. Feb 18, 2007 #3
    So is it x=(3/2)sec(theta) ?
     
  5. Feb 19, 2007 #4

    TD

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    Homework Helper

    That's right! :)
     
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