MathGroup Archive 1992

[Date Index] [Thread Index] [Author Index]

Search the Archive

[no subject]

  • To: mathgroup at yoda.physics.unc.edu
  • From: heinz at solrt.ups.circe.fr (Schulz)
  • Date: Mon, 26 Oct 92 10:47:50 +0100

an apparently trivial problem:

(i) mma knows
      Integrate[x^n  E^(-x), x] = -Gamma[1 + n, x]
    which is pretty good of it (for non-integer n, most people would have to look this up in
a book).

(ii) BUT: 

In[4]:= Integrate[x^n  E^(-a x), x]

                    n
                   x
Out[4]= Integrate[----, x]
                   a x
                  E
now, that looks pretty dumb to me, given that mma already knows the essential result
(i). There are scores of other similar examples, involving different functions, which
can be easily produced. What would be the (general, if possible) solution to this?

Sincerely,
H.J. Schulz,
Laboratoire de Physique des Solides,
Universite Paris-Sud, Orsay, France





  • Prev by Date: Plotting probability distributions
  • Next by Date: Tables of special functions
  • Previous by thread: Plotting probability distributions
  • Next by thread: Tables of special functions