Let X = {1,2,3, 4, 5, 6} and Y = {1,3,5,7,9}. Which of the following is/are relations from X to Y?
R1=(x,y):y=2+x,x∈X,y∈Y
R2=(1,1),(2,1),(3,3),4,3,5,5
R3=(1,1),(1,3),(3,5),3,7,5,7
R4={(1,3),(2,5),(2,4),7,9
X = {1,2,3, 4,5} Y = {1,3, 5, 7, 9}
(a). R1={(x,y):y=2+x,x∈X,y∈Y}
x=1 y=3x=2 y=4x=3 y=5x=4 y=6x=5 y=7
So, R is not a relation from X to Y.
(b).
R2={(1,1),(2,1),(3,3)(4,3),(5,5)} R2⊆X×Y
(c).
R3={(1,1),(1,3),(3,5)3,7(5,7)} R3⊆X×Y
(d). R4⊈X×Y