Now we will discuss moreover about relations, functions, dependent and independent variables.
In algebra, a relation is any association between the elements of one set to another i.e. domain and co-domain. Usually relation is denoted by R and it is a subset of the Cartesian product of two given sets. Elements of a relation is defined as the ordered pairs like (a,b).
The most important type of relation is function. A function is a relation in which every element from domain is mapped with exactly one element to co-domain. The elements of domain and co-domain are said to be independent and dependent variables respectively. Generally, function denoted by f.