Introduction to Trigonometry Class 10 Assertion Reason Questions Maths Chapter 8

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Hello students, we are providing assertion reason questions for class 10. 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 10 maths. In this article, you will find assertion reason questions for CBSE Class 10 Maths Chapter 8 Introduction to Trigonometry. It is a part of Assertion Reason Questions for CBSE Class 10 Maths Series.

ChapterIntroduction to Trigonometry
Type of QuestionsAssertion Reason Questions
Nature of QuestionsCompetency Based Questions
BoardCBSE
Class10
SubjectMaths
Useful forClass 10 Studying Students
Answers providedYes
Difficulty levelMentioned
Important LinkClass 10 Maths Chapterwise Assertion Reason

Assertion Reason Questions on Introduction to Trigonometry

Assertion and Reason Questions

Directions: Each of the following questions consists of two statements: an Assertion (A) and a Reason (R). Answer them by selecting the correct option:
(a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
(b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
(c) Assertion (A) is true, but Reason (R) is false.
(d) Assertion (A) is false, but Reason (R) is true.

Q1. Assertion (A): The value of $\tan \theta$ increases as $\theta$ increases from $0^{\circ}$ to $90^{\circ}$.
Reason (R): As the angle increases, the ratio of opposite side to adjacent side in a right triangle increases.

Answer: Option (a) is correct.
Explanation: Since $\tan \theta=\frac{\text { opposite }}{\text { adjacent }}$, and this ratio increases with angle in a right triangle (except at $90^{\circ}$ ), both $A$ and $R$ are true and $R$ correctly explains $A$.

Difficulty Level: Moderate

Q2. Assertion (A): $\cot \theta$ is the reciprocal of $\tan \theta$, but undefined when $\tan \theta=0$.
Reason (R): The reciprocal of zero is undefined.

Answer: Option (a) is correct.
Explanation: When $\tan \theta=0, \cot \theta=\frac{1}{0}$, which is undefined. Both A and R are correct and logically connected.

Difficulty Level: Moderate

Q3. Assertion (A): If $\sin \theta=\frac{3}{5}$, then $\cos \theta=\frac{4}{5}$.
Reason $(R)$ : In a right triangle, if one leg is 3 and the hypotenuse is 5 , then the other leg must be 4 (Pythagorean triple).

Answer: Option (a) is correct.
Explanation: This is a classic example of the 3-4-5 right triangle. The identity $\sin ^2 \theta+\cos ^2 \theta=1$ also supports this.

Difficulty Level: Easy to Moderate

Q4. Assertion (A): Trigonometric ratios are independent of the size of the triangle but depend only on the angle.
Reason (R): Trigonometric ratios are derived from similar triangles which have equal angles but proportional sides.

Answer: Option (b) is correct.
Explanation: Both statements are true: ratios depend only on the angle, and similar triangles justify this. However, the reason doesn’t directly explain why the ratios are independent of triangle size.

Difficulty Level: Tough / Conceptual

Q5. Assertion (A): $\sec \theta$ and $\csc \theta$ can never be less than 1 .
Reason (R): $\cos \theta$ and $\sin \theta$ always lie between 0 and 1 for $\theta \in\left(0^{\circ}, 90^{\circ}\right)$.

Answer: Option (a) is correct.
Explanation: Since $\sec \theta=\frac{1}{\cos \theta}$ and $\csc \theta=\frac{1}{\sin \theta}$, and $\sin \theta, \cos \theta \in(0,1]$, the reciprocals are $\geq 1$.

Difficulty Level: Tough

Also check

Topics from which assertion reason questions may be asked

  • Trigonometric Ratios
  • Values of Ratios
  • Identities

Trigonometry bridges the gap between angles and lengths in right-angled triangles.

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

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Frequently Asked Questions (FAQs) on Introduction to Trigonometry Assertion Reason Questions Class 10

Q1: What does the chapter ‘Introduction to Trigonometry’ cover?

A1: It builds key concepts related to introduction to trigonometry 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 Introduction to Trigonometry?

A3: They strengthen core concepts and boost confidence in tackling tricky scenarios from introduction to trigonometry.

Q4: Are assertion reason questions part of CBSE board exams?

A4: Yes, they are included under competency-based formats to test depth of understanding.

Introduction to Trigonometry Class 10 Assertion Reason Questions Maths Chapter 8

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