## zero :(

- leonardo shawon
**Posts:**169**Joined:**Sat Jan 01, 2011 4:59 pm**Location:**Dhaka

### zero :(

im confused.. Amm, whats correct?

real number, R={0,1,2,3,4,5....}

or R={1,2,3,4,5. . . . }

real number, R={0,1,2,3,4,5....}

or R={1,2,3,4,5. . . . }

Ibtehaz Shawon

BRAC University.

BRAC University.

*long way to go .....*### Re: zero :(

I think you mean "Natural numbers".

Different people use different definitions. It does not really matter, as long as your are consistent in what you use.

I personally, use "positive numbers" or "non-negative numbers" to get rid of the ambiguity. This is the most common convention in modern mathematics.

Different people use different definitions. It does not really matter, as long as your are consistent in what you use.

I personally, use "positive numbers" or "non-negative numbers" to get rid of the ambiguity. This is the most common convention in modern mathematics.

- leonardo shawon
**Posts:**169**Joined:**Sat Jan 01, 2011 4:59 pm**Location:**Dhaka

### Re: zero :(

thank u. But actually my question is, is Zero in Positive Real Number Set?

Ibtehaz Shawon

BRAC University.

BRAC University.

*long way to go .....*- leonardo shawon
**Posts:**169**Joined:**Sat Jan 01, 2011 4:59 pm**Location:**Dhaka

### Re: zero :(

thanks 4 Natural Number:) i didnt know that.

Ibtehaz Shawon

BRAC University.

BRAC University.

*long way to go .....*### Re: zero :(

Real number is not only integers (পূর্ণ সংখ্যা).They can be fractions, irrational numbers as well. In generals all the numbers on the real line is real numbers.

Zero is not a positive (or negative) real number. You can include zero with positive reals by considering the set of non negative reals. In the same way zero is in the set of non positive reals.

Zero is not a positive (or negative) real number. You can include zero with positive reals by considering the set of non negative reals. In the same way zero is in the set of non positive reals.

"Inspiration is needed in geometry, just as much as in poetry." -- Aleksandr Pushkin

Please

Please

**install LaTeX fonts**in your PC for better looking equations,**learn****how to write equations**, and**don't forget**to read Forum Guide and Rules.- leonardo shawon
**Posts:**169**Joined:**Sat Jan 01, 2011 4:59 pm**Location:**Dhaka

### Re: zero :(

amm,, then, if f : R - R+

what will i do? Considering Zero as a non negative or Non positive..?

what will i do? Considering Zero as a non negative or Non positive..?

Ibtehaz Shawon

BRAC University.

BRAC University.

*long way to go .....*### Re: zero :(

As Moon said, zero is not positive, not negative.

- leonardo shawon
**Posts:**169**Joined:**Sat Jan 01, 2011 4:59 pm**Location:**Dhaka

### Re: zero :(

so,, where to put it??

First prove for a>0, then a=0 and then a<0 . . . . . . ?

First prove for a>0, then a=0 and then a<0 . . . . . . ?

Ibtehaz Shawon

BRAC University.

BRAC University.

*long way to go .....*### Re: zero :(

Not sure what you mean.

Real numbers $> 0$ are positive

Real numbers $< 0$ are negative

$0$ is neither positive nor negative

Real numbers $> 0$ are positive

Real numbers $< 0$ are negative

$0$ is neither positive nor negative

- leonardo shawon
**Posts:**169**Joined:**Sat Jan 01, 2011 4:59 pm**Location:**Dhaka