> I did not know that the determinant had such an
> interpretation (signed area of a triangle). 

See sample topic 18 in "J Introduction & Dictionary"
http://www.jsoftware.com/books/help/dictionary/samp18.htm



----- Original Message -----
From: Brian Schott <[EMAIL PROTECTED]>
Date: Tuesday, August 8, 2006 4:56 pm
Subject: Re: [Jgeneral] on you left

>       Your solutions are terrific. They are just what I
> had hoped for and show so many ways to solve the problem.
> 
>       Btw, I meant the Subject to be "on youR left", if
> that was not clear. In bicycle rides this is a common
> warning from a passer.
> 
>       Boyko's answer surprises and surprised me the most.
> I did not know that the determinant had such an
> interpretation (signed area of a triangle). I am familiar
> with a similar interpretation in multivariate statistics, as
> the generalized covariance among variables in a quantitative
> data set.
> 
>       I was not aware that a determinant was defined for a
> nonsquare matrix, which Boyko defines. With that in mind I
> redefined Boyko's formula to omit the third (0 0) point and
> think I get the same result as the original forumla. So is
> the determinant really just square? (Less importantly, is
> determinant really defined for nonsquare matrices, or is the
> 0 0 vector just sort of non altering?)
> 
>       But the more important question regarding Boyko's
> solution is, how can we make the leap from my original
> problem definition to the signed area of a triangle? That
> is, I still don't understand how to defend the apparent
> isomorphism(?).


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