How to prove that R is equivalence relation

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SUMMARY

The relation R defined on the set X x X, where X = {1,2,3,...,10} and (a,b)R(c,d) if ad=bc, is proven to be an equivalence relation. The proof establishes that R is reflexive, symmetric, and transitive. Reflexivity is demonstrated using the pair (1,1), while symmetry and transitivity require explicit conditions derived from the relation's definition. The discussion concludes with a clear understanding of how to prove these properties for R.

PREREQUISITES
  • Understanding of equivalence relations in mathematics
  • Familiarity with reflexive, symmetric, and transitive properties
  • Basic knowledge of ordered pairs and Cartesian products
  • Ability to manipulate algebraic expressions
NEXT STEPS
  • Study the properties of equivalence relations in detail
  • Learn how to construct proofs for symmetric and transitive properties
  • Explore examples of equivalence relations in different mathematical contexts
  • Practice problems involving relations on finite sets
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Students studying abstract algebra, mathematicians interested in relations, and educators teaching concepts of equivalence relations.

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Homework Statement


let X = {1,2,3,..,10} define a relation R on X x X by (a,b)R(c,d) if ad=bc. show that R is an equivalence relation on X x X.


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The Attempt at a Solution



I think that the R have to be reflexive (because ad=bc). Eg. one of the subset is (1,1) which satisfy ad=bc, and reflexive. However, I don't know how to prove that R is symmetric, and transitive? thx
 
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R is symmetric if (a,b)R(c,d) if and only if (c,d)R(a,b). Write out what both of those conditions mean in terms of your relation. Same idea for transitive.
 
Got it. thanks :D
 

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