Inverse Trigonometric Functions Class 12 Assertion Reason Questions Maths Chapter 2

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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 2 Inverse Trigonometric Functions. It is a part of Assertion Reason Questions for CBSE Class 12 Maths Series.

ChapterInverse Trigonometric Functions
Type of QuestionsAssertion Reason Questions
Nature of QuestionsCompetency Based Questions
BoardCBSE
Class12
SubjectMaths
Useful forClass 12 Studying Students
Answers providedYes
Difficulty levelMentioned
Important LinkClass 12 Maths Chapterwise Assertion Reason

Assertion Reason Questions on Inverse Trigonometric Functions

Directions:
In the questions given below, there are two statements marked as Assertion (A) and Reason (R).
Read the statements carefully and choose the correct option:
(A) Both A and R are true, and R is the correct explanation of A.
(B) Both A and R are true, but R is not the correct explanation of A.
(C) A is true, but R is false.
(D) A is false, but R is true.

Q1. Assertion (A): The value of $\sin ^{-1}\left(\sin \frac{5 \pi}{4}\right)=-\frac{3 \pi}{4}$.
Reason (R): The principal value of $\sin ^{-1}(x)$ lies in $\left[-\frac{\pi}{2}, \frac{\pi}{2}\right]$.
Ans. Option (A) is correct.
Explanation: $\sin \frac{5 \pi}{4}=\sin \left(-\frac{3 \pi}{4}\right)$, and since $-\frac{3 \pi}{4}$ is not in the principal range, the actual principal value is within $\left[-\frac{\pi}{2}, \frac{\pi}{2}\right]$, which matches. Both statements are true, and the reason explains the assertion.

Difficulty Level: Medium

Q2. Assertion (A): $\cos ^{-1}\left(\cos \frac{5 \pi}{6}\right)=\frac{5 \pi}{6}$
Reason $(\mathrm{R})$ : The principal value of $\cos ^{-1}(x)$ lies in $[0, \pi]$.
Ans. Option (A) is correct.
Explanation: Since $\frac{5 \pi}{6} \in[0, \pi]$, and cosine is one-one in that interval, the inverse brings back the same angle. The reason directly supports the assertion.

Difficulty Level: Hard

Q3. Assertion (A): $\tan ^{-1}\left(\tan \frac{5 \pi}{4}\right)=-\frac{3 \pi}{4}$
Reason (R): The principal value of $\tan ^{-1}(x)$ lies in $\left(-\frac{\pi}{2}, \frac{\pi}{2}\right)$.
Ans. Option (D) is correct.
Explanation: $\tan \left(\frac{5 \pi}{4}\right)=\tan \left(-\frac{3 \pi}{4}\right)$, but the principal value must lie in $\left(-\frac{\pi}{2}, \frac{\pi}{2}\right)$, so the correct output is $-\frac{3 \pi}{4}$, which lies outside the principal value range. Hence, the assertion is false, but the reason is true.

Difficulty Level: Medium

Q4. Assertion (A): $\sin ^{-1}\left(\frac{3}{5}\right)+\cos ^{-1}\left(\frac{3}{5}\right)=\frac{\pi}{2}$
Reason (R): $\sin ^{-1}(x)+\cos ^{-1}(x)=\frac{\pi}{2}$ for all $x \in[-1,1]$
Ans. Option (A) is correct.
Explanation: This is a known identity of inverse trigonometric functions and holds true for all $x \in[-1,1]$.
The reason explains the assertion exactly.

Difficulty Level: Hard

Q5. Assertion (A): The function $f(x)=\sin ^{-1}(2 x)$ is defined for all real $x$.
Reason (R): The domain of $\sin ^{-1}(x)$ is $[-1,1]$.
Ans. Option (C) is correct.
Explanation: The reason is correct. However, the assertion is false because $\sin ^{-1}(2 x)$ is defined only when $-1 \leq 2 x \leq 1 \Rightarrow x \in\left[-\frac{1}{2}, \frac{1}{2}\right]$, not for all real x .

Difficulty Level: Medium

Also check

🚀 Boost Your Exam Prep: Get assertion reason questions for all subjects (Class 6-12) now!

Topics from which assertion reason questions may be asked

  • Principal Values
  • Basic Properties
  • Domain and Range

Inverse trig functions help us reverse angles and solve real-life geometry problems.

Assertion reason questions from the above given topic may be asked.

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Frequently Asked Questions (FAQs) on Inverse Trigonometric Functions Assertion Reason Questions Class 12

Q1: What does the chapter ‘Inverse Trigonometric Functions’ cover?

A1: It builds key concepts related to inverse trigonometric 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 Inverse Trigonometric Functions?

A3: They strengthen core concepts and boost confidence in tackling tricky scenarios from inverse trigonometric 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.

Inverse Trigonometric Functions Class 12 Assertion Reason Questions Maths Chapter 2

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