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Heklp with an integral involving the exp function

  1. Oct 19, 2009 #1


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    Hi everyone

    I've been dealing with a rather difficult (at least for me) integration problem which I am not able to find in integration tables I've been consulting.
    After a variable transformation I ended up with the following sets of integrals:

    [tex]\\int[/tex] e[tex]^{y}[/tex]/y[tex]^{2}[/tex]dy from 0 to t (t is not infinity) and

    [tex]\\int[/tex] e[tex]^{y}[/tex]/y[tex]^{3}[/tex]dy also from 0 to t and

    (sorry I could not get the integral symbol to work, so I used int instead)

  2. jcsd
  3. Oct 19, 2009 #2


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    Neither of those looks convergent (at 0) to me.
  4. Oct 19, 2009 #3
    As Halls said, they diverge at 0. The indefinite integral of exp(y)/y is a non-elementary function known as the "exponential integral" function. Your two integrals may be expressed in terms of the exponential integral function using integration by parts.
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