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Homework Help: Using Integration by Parts

  1. Feb 25, 2007 #1
    1. The problem statement, all variables and given/known data
    indefinite integral dx/((e^x)(sqrt(1-e(-2x))))
    using integration by parts evaluate the integral.

    2. Relevant equations

    integral u*dv = u*v- integral v*du

    3. The attempt at a solution

    To be completely and entirely honest i am not even sure where to start with this problem. I have finished other integration by parts homework questions in this assignment but this one i can't find something to choose for u and dv that will work out correctly.:grumpy: I have been at this problem alone from almost 2 hours. Any help would be greatly appreciated.
  2. jcsd
  3. Feb 25, 2007 #2
    Are you sure it wasn't

    [tex] \sqrt {1-e^{-2x}} [/tex]

    instead of [tex] \sqrt {1-e(-2x)} [/tex], since that is a very strange way of writing it.

    If so, just remember that [tex] \frac {1}{e^{x}} = e^{-x} = \sqrt {e^{-2x}} [/tex] and set [tex] u = e^{-2x} [/tex]
    Last edited: Feb 25, 2007
  4. Feb 25, 2007 #3
    It was supposed to be
    1/ [tex] \sqrt {1-e^{-2x}} [/tex]

    **How did you get that equation to show up that way? I just copy and pasted what you had to make it work this time and was curious how i would go about doing that.
    Last edited: Feb 25, 2007
  5. Feb 25, 2007 #4
    There is a \frac command in LaTex. To use it just type \frac {numerator}{denominator}

    So your problem would show up as:

    [tex] \int {\frac{dx}{e^{x}\sqrt{1-e^{-2x}}}[/tex]

    **Also check out this guide to LaTex typesetting
    Last edited: Feb 25, 2007
  6. Feb 25, 2007 #5
    Thank You for your help. It is really appreciated.
  7. Feb 26, 2007 #6


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    Science Advisor

    If nothing else there is a "^" key on your computer that can be used to indicate exponents.
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