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Re: Why does Inverse[M] hesitate?

• To: mathgroup at smc.vnet.net
• Subject: [mg54383] Re: Why does Inverse[M] hesitate?
• From: skirmantas.janusonis at yale.edu (Skirmantas)
• Date: Sat, 19 Feb 2005 02:32:57 -0500 (EST)
• Sender: owner-wri-mathgroup at wolfram.com

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. 

• Follow-Ups:
  • Re: Re: Why does Inverse[M] hesitate?
    • From: DrBob <drbob@bigfoot.com>
  • Re: Re: Why does Inverse[M] hesitate?
    • From: Andrzej Kozlowski <akoz@mimuw.edu.pl>