The ordered are represented by (a,b) where a∈A and b∈B. A and B are some sets. Here, a is said to be the domain and b is said to be the co-domain. A relation is a function if for every a∈A there exists a unique image b∈B. Every element in set A must have a image in set B. If an element in set A has more than one image then that relation does not represent s function. In the given question, the relation {(99, 98), (97, 96), (93, 96)} is a function because for every a there exists a unique image b.
