Let X = {1,2,3,4,5} and Y = {1,3,5,7,9}. Which of the following is/are relations from X to Y
R3={(1,1),(1,3),(3,5),(3,7),(5,7)}
If 'R' is a relation from 'A' to 'B' , then 'R' is defined as {(x,y)| x∈ A and y∈ B}
In all the ordered pairs in the realtions of R1, R2, R3 first component ∈ X and second component ∈ Y. So, R1, R2, R3are relations from X to Y.
R4 is not a relation from X to Y , because in ordered pain (7,9) the first component 7 ∉ X.