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

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

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Ian A. Mason

Posts: 18
Registered: 12/12/04
Re: -1 x -1 ?
Posted: Sep 16, 1999 5:42 PM
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let b be the additive inverse of 1 (aka -1)

thus:

b+1 = 0

thus (squaring both sides):

(b+1)(b+1) = 0

thus (multiplying out and using commutativity)

b*b + 2b + 1 = 0

thus

b*b + b + (b + 1) = 0

thus:

b*b + b + 0 = 0

thus

b*b + b = 0

b*b is the additive inverse of b (aka 1).

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