The relation R defined on the set A={1,2,3,4,5} by R=(x,y):x2−y2<16 is given by
R1={(1,1),(2,1),(3,1),(4,1),(2,3)}
R2={(2,2),(3,2),(4,2),(2,4)}
R3={(3,3),(4,3),(5,4),(3,4)
none of these
(1,2)∈R but (1,2)∉R1 or R2 or R3 so R≠R1 or R2 or R3.