zero :(

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leonardo shawon
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zero :(

Unread post by leonardo shawon » Mon Jan 17, 2011 12:28 am

im confused.. Amm, whats correct?
real number, R={0,1,2,3,4,5....}
or R={1,2,3,4,5. . . . }
Ibtehaz Shawon
BRAC University.

long way to go .....

tanvirab
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Re: zero :(

Unread post by tanvirab » Mon Jan 17, 2011 8:21 am

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.

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leonardo shawon
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Re: zero :(

Unread post by leonardo shawon » Mon Jan 17, 2011 12:12 pm

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

long way to go .....

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leonardo shawon
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Re: zero :(

Unread post by leonardo shawon » Mon Jan 17, 2011 12:13 pm

thanks 4 Natural Number:) i didnt know that.
Ibtehaz Shawon
BRAC University.

long way to go .....

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Moon
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Re: zero :(

Unread post by Moon » Mon Jan 17, 2011 12:33 pm

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.
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leonardo shawon
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Re: zero :(

Unread post by leonardo shawon » Mon Jan 17, 2011 1:51 pm

amm,, then, if f : R - R+
what will i do? Considering Zero as a non negative or Non positive..?
Ibtehaz Shawon
BRAC University.

long way to go .....

tanvirab
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Re: zero :(

Unread post by tanvirab » Mon Jan 17, 2011 10:00 pm

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

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leonardo shawon
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Re: zero :(

Unread post by leonardo shawon » Tue Jan 18, 2011 12:32 am

so,, where to put it??
First prove for a>0, then a=0 and then a<0 . . . . . . ?
Ibtehaz Shawon
BRAC University.

long way to go .....

tanvirab
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Re: zero :(

Unread post by tanvirab » Tue Jan 18, 2011 12:36 am

Not sure what you mean.

Real numbers $> 0$ are positive
Real numbers $< 0$ are negative
$0$ is neither positive nor negative

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leonardo shawon
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Re: zero :(

Unread post by leonardo shawon » Tue Jan 18, 2011 12:41 am

okayy., thank uu:-)
Ibtehaz Shawon
BRAC University.

long way to go .....

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