Re: Integration with non-numeric parameters

*To*: mathgroup at smc.vnet.net*Subject*: [mg79779] Re: Integration with non-numeric parameters*From*: ben <benjamin.friedrich at gmail.com>*Date*: Sat, 4 Aug 2007 05:53:47 -0400 (EDT)*References*: <f8v1cb$ded$1@smc.vnet.net>

On 3 Aug., 12:51, ingramfina... at gmail.com wrote: > When I use Mathematica to solve the following > y=x1/(2*sigma^2*t) > > Integrate[y, {t, .5, 1}] > > I get the following answer: > > (0.34657*x1/sigma^2) > > OK, so far, so good. It appears that I can generate an answer with a > non-numeric parameter. Note that I am looking for an answer in terms > of x1. > > But when I try It could well be, that this integral cannot be expressed in terms of simple functions. Already the case x1=0 gives you nasty ExpIntegralE-functions. Bye Ben > > q=Exp[-(x1-t)^2/2*sigma^2*t] > > Integrate[q, {t, .5,1}] > > Now Mathematica does not solve this integral, it just repeats the > command > > I am trying to get an expression in terms of x1. Why do I get a > statement like this instead of an answer? There is something about > the functional form of the integrand that is causing the problem, I > just don't know what it is. > > Any help you can give me is much appreciated!