Which numbers are in the domain of the following function? (18,2) (12,9) (4,2) (5,7) 4, 2, 5, 12, 9, 18, 7

As we know that a relation is a set of ordered pairs.

Also we know that a function is a relation in which no two different ordered pairs have the same first coordinate.

Hence the given ordered pair represents a function.

Here in the ordered pair the x-coordinate represents the domain of the function, while the y-coordinate represents the range of the function.

Hence the domain of the function represented by the above ordered pair is