Question

Let A = [1, 2, 3, 5], B = [4, 6, 9] and R be a relation from A to B defined by R = {(x, y) : x − y is odd}. Write R in roster form.

Answer 1

Given:
A = {1, 2, 3, 5} and B = {4, 6, 9}
R = {(x, y) : x − y is odd}

Since 1$-$4 = $-$3 is odd, we have:
1$-$6 = $-$5 is odd
2$-$9 = $-$7 is odd
3$-$4 =$-$1 is odd
3$-$6 = $-$3 is odd
5$-$4 = 1 is odd
5$-$6 = $-$1 is odd

∴ R = {(1,4),(1,6),(2,9),(3,4),(3,6),(5,4),(5,6)}