Is R an Equivalence Relation in R x R Based on a Quadratic Equation?

Click For Summary

Homework Help Overview

The discussion revolves around determining whether a specific relation R defined on R x R, based on a quadratic equation, is an equivalence relation. The original poster seeks to prove or provide a counterexample regarding the reflexive, symmetric, and transitive properties of this relation.

Discussion Character

  • Conceptual clarification, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to establish the properties of reflexivity, symmetry, and transitivity for the relation R, expressing confusion about how to demonstrate these properties in the context of four variables. Some participants suggest clarifying definitions and writing out the equations to aid understanding.

Discussion Status

Participants are engaged in exploring the properties of the relation R, with some providing guidance on how to approach the proof. There is an ongoing discussion about variable naming conventions and their implications for clarity in the problem.

Contextual Notes

There is a note from a moderator regarding the appropriate forum for posting homework assignments, indicating that the discussion may be part of an assigned coursework or independent study. The original poster expresses prior experience with equivalence relations but indicates uncertainty due to the complexity introduced by the quadratic equation involving four variables.

nikie1o2
Messages
7
Reaction score
0
In R x R , ley (x,y) R (u,v) if ax^2 +by^2=au^2 + bv^2, where a,b >0. Determine the relation R is an equivalnce relation. Prove or give a counter example
 
Physics news on Phys.org
Welcome to PF!

Hi nikie1o2! Welcome to PF! :smile:

(try using the X2 tag just above the Reply box :wink:)

Tell us how far you've got, and where you're stuck, and then we'll know how to help! :smile:
 


tiny-tim said:
Hi nikie1o2! Welcome to PF! :smile:

(try using the X2 tag just above the Reply box :wink:)

Tell us how far you've got, and where you're stuck, and then we'll know how to help! :smile:


Hello, thank you for the warm welcome.

I have done equivalence relations before but with just two variables not 4. So i was confused on how to prove the reflexive, symmetric & transitive properties.

For reflexive i was thinking if (x,y)R(x,y) then ax^2+by^2=ax^2+by^2- so that is true
Symmetry: (x,y)R(u,v) then (u,v)R(x,y) is true

For Transitive i knoe if(x,y)R(u,v) and (u,v)R(a,b), then (x,y)R(a,b). I am just confused on how to show the equations for that and that it's true...
 
Moderator's note:
Homework assignments or textbook style exercises for which you are seeking assistance are to be posted in the appropriate forum in our https://www.physicsforums.com/forumdisplay.php?f=152" area. This should be done whether the problem is part of one's assigned coursework or just independent study.
 
Last edited by a moderator:
Hello nikie1o2! :smile:

(Please use the X2 tag just above the Reply box :wink:)
nikie1o2 said:
For Transitive i knoe if(x,y)R(u,v) and (u,v)R(a,b), then (x,y)R(a,b). I am just confused on how to show the equations for that and that it's true...

Just write out the definitions of (x,y)R(u,v) and (u,v)R(a,b) … then it should be obvious! :smile:

(btw, the equivalence classes are a well-known geometrical shape … can you se which?)
 
Just a comment: using "a" and "b" is a bad choice of variable names in this problem. May I suggest using "s" and "t" instead? I.e., use
(u,v)R(s,t)​
instead of
(u,v)R(a,b)​
when working out the transitive property.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 2 ·
Replies
2
Views
3K
Replies
6
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K