subring?


by 1800bigk
Tags: subring
1800bigk
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#1
Nov12-05, 09:20 AM
P: 42
Let S = {R-Z}, the set of all reals that are not integers. Is S a subring of R? I think not because 1/2 is in S but 1/2-1/2=0 so S is not closed under subtraction so is not a subring.

is that right?
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mathwonk
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#2
Nov12-05, 11:43 AM
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what do you think? and why do you think it? if i say you are wrong, would you believe me? why or why not?
1800bigk
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#3
Nov12-05, 12:11 PM
P: 42
i think im right, im asking because some of the kids in my class said zero is not an integer and they said i should of picked two distinct elements to show its not closed but i said it didnt matter.

AKG
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#4
Nov12-05, 01:06 PM
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subring?


In which class are you learning about rings where the students don't believe that 0 is an integer and believe that you have to pick two distinct elements to show it's not closed?


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