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Homework Help: Solution to an integral problem

  1. Oct 19, 2011 #1
    1. The problem statement, all variables and given/known data

    The solution to the integral: [itex]f(r) = \int{ \frac{1}{r} e^{-kr}dr}[/itex]

    st. [itex]k = const ; k\in ℝ [/itex]

    2. Relevant equations

    Does this integral have a solution.

    3. The attempt at a solution

    The obvious method here might be integration by parts this being a product of functions on r. The problem arises in that the exponent does not disappear under differentiation or integration and neither does the 1/r function.

    Just affirmation that a solution exists would be sufficient.

  2. jcsd
  3. Oct 19, 2011 #2


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  4. Oct 19, 2011 #3


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    Well, the antiderivative you're looking for may not be expressible in terms of elementary functions, but the its definite integral between 0 and +infinity is a particularly nice number.
  5. Oct 19, 2011 #4
    Thank you very much.
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