Math Question: Why is -1 X -1= 1?

[dutchfire]

Now, if we know anything about math, we will know that the first branch of math is geometry. So "1" will really mean one unit of a certain length.

That will also mean that "-1" is the same length taken in the opposite direction.

As for multiplication, you can easily use the word "of" to replace it. For example, "half of three" is simply "one half multiply with three".

Hence, "-1 x -1" would mean that you take the "opposite of opposite" which really just means the same. "1 x anything" also means the "same as anything".

ok?

@bolded: Ehm, no it isn't

 

[nihilistic]

Now, if we know anything about math, we will know that the first branch of math is geometry. So "1" will really mean one unit of a certain length....

If you meant that evolutionarily, you might have a (albeit still weak) case. However, that is a question for biologists and possibly sociologists (probably not since both spacial perception and counting predate our species by a long shot), and even then you would probably have to face the the more probable evolutionary hypothesis of it beginning with counting and keeping score.

In any other circumstance, math definitely does not begin with "magnitude". In kindergarten, math begins with counting, as it is the easiest. Formally, math begins with these subjects:

Set Theory
Number Theory
Topology
Real Analysis

Why? Because those are the subjects needed to build the real number line. After that it branches out to your heart's desire.