Re: help! - questions about Integration

*To*: mathgroup at smc.vnet.net*Subject*: [mg28856] Re: help! - questions about Integration*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Wed, 16 May 2001 03:28:05 -0400 (EDT)*Organization*: Universitaet Leipzig*References*: <9dqdvp$4jv@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi, I expect serious typing errors in your equation A < (x^2+y^2)/(x^2 Y^2 x^2-y^2) < B it may be A < (x^2+y^2)/(x^4 Y^2-y^2) < B or A < (x^2+y^2)/(x^2 y^2+ x^2-y^2) < B With Mathematica 4.1 *and* the correct formula you may try Needs["Calculus`Integration`"] Integrate[ Exp[-(x/a)^2 - (y/b)^2]* Boole[A < (x^2 + y^2)/(x^2 y^2+ x^2 - y^2) < B], {x, -Infinity, Infinity}, {y, -Infinity, Infinity}] How ever your inequality does not work. Regards Jens c6wang at sciborg.uwaterloo.ca wrote: > > Hello! I am quite new about Mathematica, can someone help me out this > question? > > I want to do an integration, as written below: > > Integrate[Exp[-(x/a)^2-(y/b)^2], x and y are variables (-Infinity, > Infinity), > integration area is defined by > A < (x^2+y^2)/(x^2 Y^2 x^2-y^2) < B, > > Where a, b, A, B are invariables. > > I am wondering if Mathematica can find out a way to to this. Or there is a > function from Mathematica special for this kind of integration? > > Thank you in advance! > > Regards > > Connie