y=±√25−x2
where both x and y are integers.
Cleraly for x=0,±3,±4,±5, y will be integers as
y=±5,±4,±3,0
∴R=(0,±5),(±3,±4),(±4,±3),(±5,0)
R−1=(±5,0),(±4,±3),(±3,±4),(0,±5)
Each R and R−1 consists of 2+ 4 + 4 +2 = 12 ordered pairs.
Domain of R ={0,±3,±4,±5} = domain of R−1.