Re: Strange "not a symbol or valid symbol name" error

*To*: mathgroup at smc.vnet.net*Subject*: [mg60222] Re: Strange "not a symbol or valid symbol name" error*From*: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>*Date*: Thu, 8 Sep 2005 04:52:59 -0400 (EDT)*Organization*: Uni Leipzig*References*: <dfm86d$hek$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi, try x=.; Integrate[E^(-x) Sqrt[x^2-9], {x,3,5}] but Mathematica can't do the integral. Regards Jens "Flip" <fliptomato at gmail.com> schrieb im Newsbeitrag news:dfm86d$hek$1 at smc.vnet.net... | Greetings all, I'm using Mathematica 5.0 and have been getting a | strange error message: | | Unique::usym : | 10000000000 is not a symbol or a valid symbol name | | This comes from the following integral: | | Integrate[E^(-x) Sqrt[x^2-9], {x,3,5}] | | The limits of integration don't matter much so long as they keep the | integrand real. | | I don't understand this and am not quite sure how to fix the problem. | (It's a well defined definite integral, right? It's real in the domain | of integration and nondivergent.) | | Thanks, | Flip |