# NCERT Exemplar Class 10 Maths Chapter 8 Solutions: Introduction to Trigonometry and its Applications

NCERT Exemplar Class 10 Maths Solutions for Chapter 10 ‘Introduction to Trigonometry and its Applications’ are curated in such a manner to assist you in your homework and conceptual understanding. In this chapter of NCERT Class 10 Maths Exemplar, you will be introduced to the basics of trigonometry. You will learn about trigonometric ratios, trigonometric ratios of some specific angles and trigonometric identities. The applications of trigonometry included in the exemplar syllabus are the line of sight, angle of depression and elevation, height or length of an object.

In this chapter, questions are arranged in 4 exercises and are 60 in number. This will help you practice rigorously all possible kinds of questions that are asked in CBSE Class 10 exams. There is very less scope of mistakes in this chapter if you gain clarity in all the questions. The NCERT Exemplar solutions for the chapter are designed with this objective by our subject matter experts.

We have prepared the answers keeping in mind the level of questions in your syllabus. You will get 100% accurate solutions of the exemplar exercises of Chapter 7 at Instasolv. The answers are precise, with adequate reasoning to make sure you are not left with any doubts. It is recommended that you refer to the solutions to make the best of your self-study time.

## Important Topics in the NCERT Exemplar Class 10 Maths Solutions Chapter 8

**Introduction**

- If we consider a triangle ABC right angled at B, then the trigonometric ratios with respect to ∠A will be given as:
- When the angle remains the same, the values of trigonometric ratios also remain unchanged.
- We can determine all the trigonometric ratios for an angle if one trigonometric ratio is known.
- The value of sine and cosine of an angle is always less or equal to 1 while that of secant and cosecant of the angle is always greater than 1.

**Complementary Angles**

The pair of complementary angles cosine-sine, tangent-cotangent, and secant-cosecant such that:

- sin(90-A)=cosA, cos(90-A)=sinA
- tan(90-A)=cotA, cot(90-A)=tanA
- cosec(90-A)=secA, sec(90-A)=cosecA

**Trigonometric Identities**

Following are the important identities:

- cos
^{2}A+sin^{2}A=1 - 1+tan
^{2}A=sec^{2}A - cot
^{2}A+1=cosec^{2}A

**Applications of Trigonometry**

- The line joining the point where the eye of the observer lies to the point of object being viewed is known as the ‘line of sight’.
- If the object being observed is above the horizontal, the angle between the line of sight and horizontal is termed as ‘angle of elevation’.
- If the object being viewed is below the horizontal, the angle between the line of sight and horizontal is termed as ‘angle of depression’
- Therefore, with the help of trigonometric ratios, we can evaluate the height and length of the objects under study or the distance between two points or objects.

### Exercise Discussion of NCERT Exemplar Class 10 Maths Solutions Chapter 8: Introduction to Trigonometry and its Applications

- Exercise 8.1 comprises 15 multiple-choice questions covering topics such as finding the values of trigonometric ratios of different angles.
- Exercise 8.2 questions will need you to check the correct statements with reasoning. To be able to answer these questions, you should be able to use the trigonometric identities proficiently.
- Exercise 8.3 questions are short answer type ones and are important for the board exams. The questions are formula-based.
- The questions in exercise 8.4 are all analytical in nature and will help you extensively practice the applications of trigonometric identities.
- The NCERT Exemplar questions cover the pattern of questions of all the exams of your level.

### Why Use NCERT Exemplar Class 10 Maths Solutions Chapter 8: Introduction to Trigonometry and its Applications by Instasolv?

- You can easily access the NCERT Class 10 Exemplar Solutions for all problems of Maths Chapter 8 at Instasolv.
- We make sure that our answers are interactive and inclusive in nature with our expert faculty.
- At Instasolv, you will find the perfect answers that you can employ in your homework as well as CBSE school exams.