Let R1 = {(a, b) \[\in\] N \[\times\] N : |a - b| \[\le\] 13} and
R2 = {(a, b) \[\in\] N \[\times\] N : |a - b| \[\ne\] 13}. Then on N :
Solutions · 1
Official solution
R1={(a,b)∈N×N:∣a−b∣≤13} and
R2={(a,b)∈N×N:∣a−b∣=13}
In R1:∵∣2−11∣=9≤13∴(2,11)∈R1 and (11,19)∈R1 but (2,19)∈/R1∴R1 is not transitive
Hence R1 is not equivalence
In R2:(13,3)∈R2 and (3,26)∈R2 but (13,26)∈/R2(∵∣13−26∣=13)∴R2 is not transitive
Hence R2 is not equivalence.