Give an example of a relation in real life, and explain why it is a function.

Answer 1

One example of a relation in real life that is a function is the relation between a student and their assigned student ID number in a school.

In this example, every student in the school is assigned a unique student ID number. Each student has only one ID number, and there is no student who shares the same ID number with another student. Therefore, for every student, there is exactly one corresponding student ID number assigned to them.

This relation satisfies the criteria of a function because it is a set of ordered pairs, where each student is paired with their corresponding student ID number. It is also a function because each student is associated with exactly one student ID number, and no student is associated with more than one ID number. Moreover, there is no student in the school who does not have an assigned student ID number, ensuring that the relation is a total function.