1. Is it correct to define |x| as the distance from zero to x?

2. It's also the distance from zero to minus x.

3. If that is true, can I say ?

4. I take it x is just an ordinary, real number? That isn't really the definition, which is this (for real x):

However, more often than not you would define the "distance" between the real numbers x and y as |x - y|, so in essence you are right.

Edited to add: Ah, I just saw your second post. If x can be complex, the notation |x| is use for the modulus of x, which in terms of the real and imaginary parts of x is

By Pythagoras' theorem, |x| is the length of the arrow representing x in the Argand plane. For values of x which happen to lie on the real axis, this definition coincides with the first definition I gave above.

5. What about complex numbers? Would give me the "size" of the number or what?

P.S.- Look at that! I learned how to use the tex tags xD

6. Originally Posted by pienapple27
What about complex numbers? Would give me the "size" of the number or what?
Yep (I edited my previous post to cover this - see above).

Originally Posted by pienapple27
P.S.- Look at that! I learned how to use the tex tags xD

7. Just to wrap it up:
Complex number --> , being a the real part and b the imaginary part.

Ex:

That's 'bout it right?

P.S.- I've edited this 100 times but I can't get my square root to go over all the stuff in parenthesis like you did. What's the secret?

8. Originally Posted by pienapple27
Just to wrap it up:
Complex number --> , being a the real part and b the imaginary part.

Ex:

That's 'bout it right?
Yes, that's it.

Originally Posted by pienapple27
P.S.- I've edited this 100 times but I can't get my square root to go over all the stuff in parenthesis like you did. What's the secret?
You need curly braces, like this: $$\sqrt{1^2 + 2^2}$$.

By the way, if you ever want to see how a LaTeX formula was written by someone, try double-clicking on it. It should bring up the LaTeX code.

9. Oh cool, thanks!

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