Re: [Phys-L] closed vectors

[Roger Haar <haar@physics.arizona.edu>]

Hi,
    "Closed"  implies that the cross product
any members of the set is in the original
set of unit vectors.

For example if your original set contains only
the unit vector x and y, the question becomes
is the cross product of x and y in the original
set of unit vectors.  It is not because

x  CROSS y  is  z.

And z is not in the original set.

If your origin set of unit vectors was x, y,
and z, the set would be closed with
respect to cross products. (At least up to
a minus sign)

Thanks Roger




On 10/6/2014 11:32 AM, Paul Lulai wrote:
> Hello.
> I am working through some problems and came upon a question I need some help with.
> I have some basic unit vectors and I am asked if the set of unit vectors are closed when crossed.
> It's been a while.
> > From what I recall, closed simply means the vectors would create an enclosed shape.
> - is this a correct interpretation?
> - if not, could you clarify?
>
> I have no recollection of why this knowledge would be helpful for dot or cross products. Since it was asked, I imagine I am missing something.
> - what am I missing (I assume quite a bit here)?
>
> Thanks for any insight you can provide.
> Have a good one.
> Paul.
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