Question

If R = {(x, y) : x, y ∈ Z, x² + y² = 25}, then Domain (R) = .................... and Range (R) = __________.

Answer 1

If R = { (x, y) : x, y ∈ Z , x² + y² = 25}
Since x² + y² =25
$\therefore$ only possibilities for x are 0, 3, 4 and 5 and similarly for y are 0, 3, 4 and 5
i.e R = {(0, 5) , (3, 4) , (4, 3), (5, 0)}
{$\because$ all above satisfy x² + y² = 25}
$\therefore$ Domain (R) = {0, 3, 4, 5}and Range (R) = {0, 3, 4, 5}