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

*To*: mathgroup at smc.vnet.net*Subject*: [mg54456] Re: [mg54383] Re: Why does Inverse[M] hesitate?*From*: DrBob <drbob at bigfoot.com>*Date*: Sun, 20 Feb 2005 00:11:17 -0500 (EST)*References*: <200502190732.CAA06180@smc.vnet.net>*Reply-to*: drbob at bigfoot.com*Sender*: owner-wri-mathgroup at wolfram.com

>> If I do justA={{a,b},{c,d}} >> B={{e},{f}} >> Inverse[A].BI get the final correct result. If a d != b c, you mean. I'm not sure why Inverse is more finicky in the other case, where C == 0 and/or C g + P w - g P w == 0 would make the inversion meaningless. Bobby On Sat, 19 Feb 2005 02:32:57 -0500 (EST), Skirmantas <skirmantas.janusonis at yale.edu> wrote: > 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. > > > > -- DrBob at bigfoot.com www.eclecticdreams.net

**References**:**Re: Why does Inverse[M] hesitate?***From:*skirmantas.janusonis@yale.edu (Skirmantas)