Yahoo Answers: Answers and Comments for Relations definition help  don't understand? [Mathematics]
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From Anonymous
enUS
Tue, 25 Jun 2019 06:56:36 +0000
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Yahoo Answers: Answers and Comments for Relations definition help  don't understand? [Mathematics]
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https://answers.yahoo.com/question/index?qid=20190625065636AAqtSLt
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From husoski: The values in the pairs of R come from the def...
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https://answers.yahoo.com/question/index?qid=20190625065636AAqtSLt
Tue, 25 Jun 2019 09:28:51 +0000
The values in the pairs of R come from the definition of the relation as: {(a,b)  a divides b}. (1,2) is in the relation R since the a value (1) evenly divides the b value (2). (Remember that "a divides b" means that integer division of (b) by (a) has a remainder of zero.) The pair (2,3) is not in the relation because 2 does not divide 3.
The numbers in A = {1, 2, 3} are simply made up; but you probably figured that out. :^)

From RealPro: Oh hey look google is there!
The way we frequ...
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https://answers.yahoo.com/question/index?qid=20190625065636AAqtSLt
Tue, 25 Jun 2019 09:19:07 +0000
Oh hey look google is there!
The way we frequently describe a relation in writing is using a set of ordered pairs (x,y).
The example was clearly written in a caffeine induced frenzy since they really did not say what a and b are.
a and b are obviously supposed to be any two numbers from the set A.
Since 1 divides 1, then (1, 1) is a pair that obeys the relation so you put it in R.
Since 1 divides 2, then (1, 2) is also such a pair.
Obviously order is important. 2 does not divide 1 hence (2, 1) is not an appropriate pair  we say the relation is not "symmetric".
A relation such as T = { (a,b)  a^2 = b^2 } is symmetric because obviously if a pair (a, b) obeys the relation then so does (b, a)
(1)^2 = 1^2 and 1^2 = (1)^2