Re: Re: Why does Inverse[M] hesitate?

*To*: mathgroup at smc.vnet.net*Subject*: [mg54404] Re: [mg54383] Re: Why does Inverse[M] hesitate?*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Sun, 20 Feb 2005 00:08:04 -0500 (EST)*Reply-to*: hanlonr at cox.net*Sender*: owner-wri-mathgroup at wolfram.com

Don't include the MatrixForm wrapper in the definition of the variables (A={{(1-g)-1,1},{-w P(1-g)/C,-1}})//MatrixForm (B={{0},{-P(w+1)}})//MatrixForm Inverse[A].B Bob Hanlon > > From: skirmantas.janusonis at yale.edu (Skirmantas) To: mathgroup at smc.vnet.net > Date: 2005/02/19 Sat AM 02:32:57 EST > To: mathgroup at smc.vnet.net > Subject: [mg54404] [mg54383] Re: Why does Inverse[M] hesitate? > > The Inverse function sometimes calculates the inverse of a matrix > immediately, sometimes it does not. Try this example in Mathematica > 5.1: > > A={{(1-g)-1,1},{-w P(1-g)/C,-1}}//MatrixForm > B={{0},{-P(w+1)}}//MatrixForm > > I get > Out: Inverse[(expanded A)].(expanded B) > > If I do just > A={{a,b},{c,d}} > B={{e},{f}} > Inverse[A].B > > I get the final correct result. > >