Relation & Functions Basic concepts on relations and functions chapter 2 of class 11, basic point based on the topic relation and functions. Different types of functions and their graphs. Introduction In our daily life we come across different types of relations like brother and sister, father and son, husband and wife etc. Topics to be discussed Here Ordered Pair Cartesian Product of two sets Relations complete explanations. Domain, Range and Co-domain of relations. Functions and Different types of functions. Graphs of the Functions. Undefined Terms. Cartesian Product of two sets If A and B are two sets then Cartesian product A X B is the set of all ordered pairs of elements from A to B, i.e. A X B = { (a, b) : a ∈ A, b ∈ B } First element of all the ordered pair belongs to set A and second element belongs to set B. If either A or B is a null set, then A X B will also be empty set. In this case we can write A X B = φ