1. ## mathmatics and functions

if I'm defining the range of a function would the following be valid documentation?

Function and rule:

f(x)=x^2

Range f(x) = {f(x)|f(x)>=0}

or is it better to write the range similar to the following.

since,

f(x)=y

then,

Range f(x) = {y|y>=0}

My question is just which is the preferred method of documentation of the mathematician world?

2. *EDITED OUT*

3. This fits in general chat.
There are many ways of denoting the range in mathematics. Which one is favored really depends on the branch of mathematics (not all sets that you would want to map a function into have the string ordering, <, or the weak ordering, <=, for example), and on personal preference. I'd be inclined to favor the first version you posted.

4. sorry me im REALLY sleepy and i think i misread his post lol. I'll go to sleep before i cause more troubles

5. Haha... Sleep? What is this you speak of?

6. thank you.
sorry if my question isn't to clear.
I know two languages.
My native tounge is bad english, but I have been know to talk in a newer dialect called worst english.
;0)

7. Of those two notations, I'd prefer the second one.

8. so are you people just trying to confuse me because of the new homework post?
I thought my questions on mathmatics have been very clear, and do not ask for you to do the homework for me. now i'm confused, if this is asking to much or violating the homework rule could someone tell me. I do believe both would be technically correct, but the usage would probably be personal preferrence.

9. I think the first notation looks very strange. If you want to use f(x), just write:
{f(x)|x€R}
{x^2|x€R}
or
f(x)>=0
Because range(f) is every possible value of f.

10. I'd be more likely to write something like:
f >= 0 (where the variable is implicit)... but that's just me.

Use which ever notation you prefer (or, which ever one your teacher prefers ).

11. Sang-drax
how did you get the element symbol? is that a currency format?
{f(x)|x€R}
{x^2|x€R}
thanks for everyones input on this question.