Class 9 Math Chapter 3 Sets & Functions Notes PDF Download (New Syllabus)
Class 9 Math Chapter 3 Sets & Functions is a very important chapter that builds a strong foundation for students. In this chapter, you will learn about sets, subsets, union, intersection, and functions, which are essential concepts for higher-level mathematics.
If you want to prepare well for exams, downloading notes is not enough — you must understand the concepts. In this article, you will get a complete explanation, solved examples, and practice questions, along with a PDF download link at the end.
📌 What is a Set?
A set is a collection of well-defined objects.
✅ Example:
A = {1, 2, 3, 4}
👉 Here, the group of numbers is called a set.
📌 Types of Sets
1. Finite Set
A set with a limited number of elements.
👉 Example:
A = {1, 2, 3}
2. Infinite Set
A set with unlimited elements.
👉 Example:
Natural numbers = {1, 2, 3, 4, ...}
3. Empty Set
A set with no elements.
👉 Example:
A = {}
📌 Subsets (Important Concept)
If all elements of set A are present in set B, then A is called a subset of B.
👉 Example:
A = {1, 2}
B = {1, 2, 3, 4}
👉 A ⊆ B
📌 Operations on Sets
🔹 Union (∪)
The combination of all elements from both sets.
👉 Example:
A = {1, 2}
B = {2, 3}
👉 A ∪ B = {1, 2, 3}
🔹 Intersection (∩)
The common elements between two sets.
👉 Example:
A ∩ B = {2}
📌 What is a Function?
A function is a relation where each input has exactly one output.
👉 Example: f(x) = x²
If x = 2
👉 f(2) = 4
📊 Solved Examples
✅ Example 1:
A = {1, 2}, B = {2, 3}
Find A ∪ B
👉 Solution:
A ∪ B = {1, 2, 3}
✅ Example 2:
Find A ∩ B
👉 Solution:
A ∩ B = {2}
📝 Practice Questions
A = {1, 2, 3}, B = {3, 4, 5}
👉 Find A ∪ B
Find A ∩ B
Write an example of an empty set
Define subset with an example
If f(x) = x², find f(3)
You can download the complete notes PDF from the link below:
https://drive.google.com/file/d/1uiadeFcZErK7nEjuMDcXrngBTrx9zBDz/view?usp=drivesdk
Comments
Post a Comment