Question:
Let R be a relation in N defined by (x, y) ∈ R ⇔ x + 2y =8. Express R and R−1 as sets of ordered pairs.
Solution:
Let R be a relation in N defined by (x, y) ∈ R ⇔ x + 2y = 8.
We have:
x = 8
For y = 3, 2, 1, we have:
x = 2, 4, 6
∴ R = {(2, 3), (4, 2), (6, 1)}
And,
R−1 = {(3, 2), (2, 4), (1, 6)}