A = { 1, 2, 3, 4 } On this set A binary relations are defined. Indicate all the SYMMETRICAL Relations. R 1 = { (1,1), (2,2), (3,3), (4,4) } R 2 = {(1,1), (2,2), (3,3)} R 3 = { (1,1), (2,2), (3,3), (4,4), (1,3), (3,4), (1,4) } R 4 = { (1,1), (2,2), (3,3), (4,4), (1,3), (3,1), (3,4), (1,4) } R 5 = {(2,3)} R 6 = { (2,3), (3,4)}

A symmetric relation is a type of binary relation which means is equals to. That means if in a set (a,b) is present than there must be (b,a) presented also. `Checking for R1 (1,1)=(1,1) (2,2)=(2,2) (3,3)=(3,3) (4,4)=(4,4) hence R1 is symmetrical relation. checking for R2 similar case as R1, hence R2 is symmetric checking for R3 (1,3) is present but (3,1) is not present (3,4) is present but (4,3) is not present (1,4) is present but (4,1) is not present Hence R3 is not symmetrical relation Checking for R4 (3,4) is present but (4,3) is not present (1,4) is present but (4,1) is not present Hence R4 is not symmetrical relation checking for R5 (2,3) is present but (3,2) is not present Hence R5 is not symmetrical relation Checking for R6 (2,3) is present but (3,2) is not present (3,4) is present but (4,3) is not present Hence R6 is not a symmetric relation