Question:
The relation R = {(x, y) : x, y ∈ Z, x2 + y2 = 64} is __________.
Solution:
R = {(x, y) : x, y ∈ Z : x2 + y2 = 64}
Since
x2 + y2 = 64
y2 = 64 − x2
The only possibilities for x are 0, 8 and −8, and for y are 0, −8 and 8 .
i.e R = {(0, 8), (8, 0), (−8, 0) (0, −8)}
Hence R = { (0, 8) (−8, 0) (8, 0) (0, −8)}