Last Updated on April 17, 2025 by XAM CONTENT
Hello students, we are providing assertion reason questions for class 12. Assertion Reason questions are the new question format that is introduced in CBSE board. The resources for assertion reason questions are very less. So, to help students we have created chapterwise assertion reason questions for class 12 maths. In this article, you will find assertion reason questions for CBSE Class 12 Maths Chapter 1 Relations and Functions. It is a part of Assertion Reason Questions for CBSE Class 12 Maths Series.
| Chapter | Relations and Functions |
| Type of Questions | Assertion Reason Questions |
| Nature of Questions | Competency Based Questions |
| Board | CBSE |
| Class | 12 |
| Subject | Maths |
| Useful for | Class 12 Studying Students |
| Answers provided | Yes |
| Difficulty level | Mentioned |
| Important Link | Class 12 Maths Chapterwise Assertion Reason |
Assertion Reason Questions on Relations and Functions
Q1. Assertion (A): Every identity function is one-one and onto.
Reason (R): An identity function maps each element to itself.
Difficulty Level: Medium
Ans. Option (A) is correct.
Explanation: The identity function $f(x)=x$ satisfies both injectivity (one-one) and surjectivity (onto), and the reason correctly supports this.
Q2. Assertion (A): The composition of two invertible functions is always invertible.
Reason (R): If $f$ and $g$ are invertible, then $(f \circ g)^{-1}=f^{-1} \circ g^{-1}$.
Ans. Option (C) is correct.
Explanation: While the composition of two invertible functions is indeed invertible, the formula given is incorrect. It should be:
$$
(f \circ g)^{-1}=g^{-1} \circ f^{-1}
$$
Hence, Assertion is true, Reason is false.
Difficulty Level: Hard
Q3. Assertion (A): A function $f: A \rightarrow B$ is onto if every element of $B$ is mapped by some element of $A$.
Reason (R): In an onto function, the range of $f$ is equal to the codomain.
Ans. Option (A) is correct.
Explanation: Both statements describe the same property of an onto (surjective) function, and the reason directly explains the assertion.
Difficulty Level: Medium
Q4. Assertion (A): The function $f(x)=x^2, x \in \mathbb{R}$, is invertible.
Reason (R): An invertible function must be one-one and onto.
Ans. Option (D) is correct.
Explanation: The function $f(x)=x^2$ is not one-one over $\mathbb{R}$, since $f(2)=f(-2)=4$. So it’s not invertible on $\mathbb{R}$, although the reason itself is true in general.
Difficulty Level: Hard
Q5. Assertion (A): If $f: A \rightarrow B$ and $g: B \rightarrow C$ are both bijective, then $g \circ f$ is also bijective.
Reason (R): A composition of two bijections is always bijective.
Ans. Option (A) is correct.
Explanation: This is a standard theorem in composite functions: bijectivity is preserved under composition, and the reason clearly supports the assertion.
Difficulty Level: Hard
Also check
- Probability Class 12 Assertion Reason Questions Maths Chapter 13
- Linear Programming Class 12 Assertion Reason Questions Maths Chapter 12
- Three Dimensional Geometry Class 12 Assertion Reason Questions Maths Chapter 11
- Vectors Class 12 Assertion Reason Questions Maths Chapter 10
- Differential Equations Class 12 Assertion Reason Questions Maths Chapter 9
- Applications of the Integrals Class 12 Assertion Reason Questions Maths Chapter 8
- Integrals Class 12 Assertion Reason Questions Maths Chapter 7
- Applications of Derivatives Class 12 Assertion Reason Questions Maths Chapter 6
- Continuity and Differentiability Class 12 Assertion Reason Questions Maths Chapter 5
- Determinants Class 12 Assertion Reason Questions Maths Chapter 4
- Matrices Class 12 Assertion Reason Questions Maths Chapter 3
- Inverse Trigonometric Functions Class 12 Assertion Reason Questions Maths Chapter 2
- Relations and Functions Class 12 Assertion Reason Questions Maths Chapter 1
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Topics from which assertion reason questions may be asked
- Types of Relations
- Types of Functions
- Composition of Functions
- Binary Operations
Understanding relations and functions is key to connecting algebra with real-world modeling.
Assertion reason questions from the above given topic may be asked.
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Frequently Asked Questions (FAQs) on Relations and Functions Assertion Reason Questions Class 12
Q1: What does the chapter ‘Relations and Functions’ cover?
A1: It builds key concepts related to relations and functions and prepares you for logical reasoning-based questions.
Q2: What are assertion reason questions?
A2: These consist of two statements: an assertion and a reason. Students need to determine their correctness and relationship.
Q3: Why practice assertion reason questions in Relations and Functions?
A3: They strengthen core concepts and boost confidence in tackling tricky scenarios from relations and functions.
Q4: Are assertion reason questions part of CBSE board exams?
A4: Yes, they are included under competency-based formats to test depth of understanding.
