For the relation R1 defined on R by the rule (a,b)ϵR1⇔1+ab>0.
Prove that : (a,b)ϵR1 and (b,c)ϵR1
⇒(a,c)ϵR1 is not true for all a,bcϵR
Let (1,−12)ϵR1 and (−12,−4)ϵR1 ⇒1+1×−12>0 and 1+(−12)−4>0 But, 1+1×(−4)=1−4 =−3<0 So, (1,−4)/ϵR1