Consider the following relations:;. Then:
- Aneither nor is an equivalence relation
- Bis an equivalence relation but is not an equivalence relation
- Cand both are equivalence relations
- Dis an equivalence relation but is not an equivalence relation
Solution & Step-by-step Explanation
1. For : . If , for any . If , then (rational). But if and , is impossible. is not symmetric (if , , , but ). Thus not an equivalence relation.2. For : . This is the standard equality relation on rational numbers, which is reflexive, symmetric, and transitive. Thus is an equivalence relation.