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Homework Help: A couple questions on integration

  1. Feb 1, 2006 #1
    Hey everyone,
    I've been having a little trouble with a few HW questions. If you guys could point me in the direction (ie- help me find the method to solve) I would really appreciate it. The q's are:
    1. The definite integral from 3 to 8 of- x^4(ln3x)dx
    For this one I am not sure wether I should make a substitution of y=3x and then do integration by parts or if there is an easier method.
    2. The indefinite integral of- 27x^2(cos(3x))
    Again I think that a substitution may be necessary although I can't seem to figure out what it is.
    Thanks to anyone who can help me out!!!
  2. jcsd
  3. Feb 1, 2006 #2


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    Science Advisor
    Homework Helper

    HINT: Try integration by parts. :)
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