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   sci.math.symbolic      Symbolic algebra discussion      10,432 messages   

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   Message 8,519 of 10,432   
   hebisch@math.uni.wroc.pl to Richard Fateman   
   Re: integral for fun   
   03 Mar 14 07:24:14   
   
   On Friday, February 28, 2014 11:33:56 PM UTC-5, Richard Fateman wrote:   
   > I don't consider a solution that includes   
   > Si, Ci, or hypergeometric functions as a solution   
   > in closed form in terms of elementary functions.   
   >   
   > Unless there is no way of expressing the answer in   
   > terms of elementary functions.   
   >   
   > After all, you could always decide that the   
   > difficult integral in question deserves its own   
   > name, say  FooI,  and then return the answer in terms   
   > of FooI.   
      
    _Indefinite_ integral above can not be done using elementary   
   functions.  For such integral 'li' and 'Ei' play the same   
   as logarithms.  'Ci' and 'Si' are similar to 'atan'.   
   As long as CAS can compute needed limits at infinity computing   
   indefinite integral in terms of special functions   
   is valid method of computing definite integral.   
   And it is much more general than methods based on   
   residue theorem.   
      
   Waldek Hebisch   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)   

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