Date: Nov 30, 2012 6:40 PM
Author: Clyde Greeno @ MALEI
Subject: Re: Some important demonstrations on negative numbers
On careful analysis, "i" is simply the unit along the *image axis*

(perpendicular to the *object axis*). It is only because of our interest in

the ("cyclonic") combinations, a*(c,d) + b*(-d,c) that the "multiplication"

of "complexes" ... (a,b)*(c,d) ... results in (0,1)*(0,1) = (-1,0). In the

non-symbolic form, "multiplication by i" simply amounts to counter-clockwise

rotation by 90-degrees.

- --------------------------------------------------

From: "Robert Hansen" <bob@rsccore.com>

Sent: Friday, November 30, 2012 4:42 PM

To: <math-teach@mathforum.org>

Cc: <math-teach@mathforum.org>

Subject: Re: Some important demonstrations on negative numbers

> Doubled.

>

> Bob Hansen

>

> On Nov 30, 2012, at 5:01 PM, Jonathan Crabtree

> <sendtojonathan@yahoo.com.au> wrote:

>

>>>

>>> On Nov 29, 2012, at 4:20 PM, Jonathan Crabtree

>> wrote:

>>>

>>>>> So what is i? I mean "i" as in the sqrt(-1), not

>>> the

>>>>> pronoun.

>>>>>

>>>>> Bob Hansen

>>>>

>>>> If you were to write the above using words only,

>>> without both abbreviations and symbols, what would

>>> you write?

>>>

>>>

>>> What number multiplied by itself once then added to

>>> one is zero?

>>>

>>> Bob Hansen

>>

>> OK thanks Bob. That was a great answer! Please keep playing along with

>> the next question. You might even get your son to answer with just a

>> single word...

>>

>> A number added to itself once, is said to have been WHAT?

>>

>> A number added to itself once, is said to have been...

>>

>> ==========

>> Thank you!