one integral - three (different) answers

*To*: mathgroup at yoda.physics.unc.edu*Subject*: one integral - three (different) answers*From*: Michael.Trott at physik.tu-ilmenau.de*Date*: Thu, 4 Feb 1993 18:59:02 +0000

Hi, the following is a little bit disturbing Integrate[1/((a-x)(x-b)),{x,-Infinity,c}] or Integrate[-1/((x-a)(x-b)),{x,-Infinity,c}] or ((#/.x->-Infinity) - (#/.x->c))&[Integrate[1/((a-x)(x-b)),x]] gives three different answers. Let c<a<b for convenience, so the independence of the two definite integrals from c is surprisingly. Whats going on? Michael Trott trott at physik.tu-ilmenau.de