Q.

Let R1 and R2 be two relations defined on ℝ by aR1b⇔ab≥0 and aR2b⇔a≥b. Then

1 R1 is an equivalence relation but not R2  
2 R2 is an equivalence relation but not R1  
3 Both R1 and R2 are equivalence relations  
4 Neither R1 nor R2 is an equivalence relation  

Ans.

(4)

a=1, b=0, c=-2 then transitive fails for R1