Re: i,j,k -- OK, how do the students get it?

[brian whatcott <inet@INTELLISYS.NET>]

At 19:17 9/18/99 -0400, John Ertel wrote:
> ...  The magnitude contains both the
> "amount" of the vector and its units.  The direction is contained by a
> unit vector which has magnitude of ONE (hence its name). ...
> This definition also does away with any need to talk about specific axes
> when dealing with the concept of unit vectors....
>                       / Prof. John P. Ertel \

> On Fri, 17 Sep 1999, David Bowman wrote:
>
> > > ... What do you tell an inquisitive student *what it
> > > means* that a vector points in the x-direction with magnitude 1?  Or even
> > > (forget about the magnitude for now) just what *it means* that a vector
> > > points in a given direction?  What does pointing in a direction *mean*?

> > > David Bowman

I was comfortable with John Ertel's approach.
Specifically in answer to David's quoted question, "What does pointing in
a direction *mean*? I want to say that a direction does not necessitate
three *orthogonal* directions to define it in some co ordinate system -
that's limiting:
  axes need only be mutually non-parallel.



brian whatcott <inet@intellisys.net>
Altus OK