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Re: please solve

• To: mathgroup at smc.vnet.net
• Subject: [mg52944] Re: please solve
• From: "Robert M. Mazo" <mazo at uoregon.edu>
• Date: Fri, 17 Dec 2004 05:19:32 -0500 (EST)
• Organization: University of Oregon
• References: <cprk0m$r87$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

On Thu, 16 Dec 2004 09:20:22 +0000 (UTC), rcmcll at yahoo.com wrote:

>Greetings:
>
>Could someone please solve this symbolically?
>This is just the ols formula for beta-hat but I need a symbolic
>solution for this special case.
>
>b = inv(x'x)x'y
>
>where
>
>x =  1  t  t^2
>1  t  t^2
>1  t  t^2
>
>
>and simplify simplify simplify!!
>
>Thanks,
>
>Bob

If I understand the notation, x is a matrix.  Yes?  If so, x is
singular and doesn't have an inverse.  Hence neither does x'x, so the
problem has no solution.  Or, better put, the problem is ill posed.

A dsifferent Bob