### Theory:

Sets
A set is a collection of well-defined distinguishable objects.
The set is denoted by a capital letter, whereas the elements of a set are represented by small letters written within the curly braces $$\{ \}$$.
Example:
$$A$$ is the set of all even numbers less than $$10$$.
$$A =$$ $$\{2, 4, 6, 8\}$$

We will extend the concept of sets in the following two forms.
• Functions
• Relations
Almost every day-to-day situations can be mathematically represented either through a function or a relation.
Some real-life examples of functions and relations
• The height of a person at a particular age can be expressed as a function.

• The area and volume of geometrical figures can be expressed as a function with one or more variables.

• The temperature at a particular season represents a relation.

To extend sets to functions and relations, we need to know the cartesian product of two non-empty sets, which we will discuss in the upcoming exercises.

Important!
Refer below to recall set operations.

Reference:
https://pixabay.com/photos/seasons-4-seasons-four-seasons-5880235/