Drexel dragonThe Math ForumDonate to the Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » sci.math.* » sci.math

Topic: -1 x -1 ?
Replies: 29   Last Post: May 13, 2009 9:01 AM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Dave L. Renfro

Posts: 4,791
Registered: 12/3/04
Re: -1 x -1 ?
Posted: Jan 22, 2009 12:39 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Tay wrote:

> -1 *-1 = 1 huh?
> Well, think of it like this:
> The minus (negative) signs cancel eachother out:
> (-1)(-1)=
> [(-)(-)](1x1)=
> So then, multiply the + and numbers:
> (+)(1x1)=
> You've got positive 1:
> +1
> It's so simple.

It's simpler than what you wrote. The signs don't cancel.
Indeed, this begs the question of how what exists (the two
negative signs) can change to a state of not existing.
Instead, the two negative signs combine to form a positive
sign: - - becomes, after rotating one of the negative signs
so that it is perpendicular to the other negative sign, +.

It's that simple.

Dave L. Renfro

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2016. All Rights Reserved.