Re: integration problem???

*To*: mathgroup at smc.vnet.net*Subject*: [mg9316] Re: integration problem???*From*: Bill Bertram <wkb at ansto.gov.au>*Date*: Mon, 27 Oct 1997 02:47:31 -0500*Organization*: ANSTO*Sender*: owner-wri-mathgroup at wolfram.com

J. M. Reese wrote: > > I am trying to integrate the expression: ((2*r2-r1-r).^5).*(r.^(-8)) > with respect to r, between the limits r1=4.75e-4 to r2=2.25e-4. > > If I use Mathematica I get 1.9567e10 If I use quad8 in Matlab I get > 1.156e07 > > Does anyone know what is going wrong with this, please? Check your Mathematica input. The correct answer is 1.156e07. As an indefinite integral your integral can be done analytically. Using Mathematica 3.0, the numerical integration and the analytic integration both give the same correct result. I can only assume you have made a typing error in your input to Mathematica. Cheers, Bill