1. ## Equivalence Classes

How many equivalence classes does this have?

{(x,y)|x^2 = y^2 mod 9}

2. Originally Posted by colombianita2089
How many equivalence classes does this have?{(x,y)|x^2 = y^2 mod 9}
Let's be clear on some points.
Is this a relation on the integers?
Are you saying that (-4,14) would belongs to the relation?

3. its a relation on N {0,1,2.....}

4. Originally Posted by colombianita2089
its a relation on N {0,1,2.....}
Well how many remainder classes modulo nine for $k^2$ are there?