NCERT Solutions for Class 11 Maths Chapter 3 – Trigonometric Functions

NCERT Solutions for Class 11 Maths Chapter 3 Trigonometric Functions consist of exercise-wise NCERT Solutions for the chapter. Trigonometry is an important topic in class 11 not only for exam purposes but also for preparation of competitive exams like JEE and NEET. This is why our best subject matter experts have solved every question for you so that you can find quick solutions to all your queries.

Chapter 3 of Class 11 Maths NCERT book has 4 exercises and 62 questions. The questions are related to finding the radian measures corresponding to the degree measures, finding degree measures corresponding to the radian measures, finding radian of a wheel where the number of revolutions made in one minute by the wheel is given, finding the degree measure of an angle, finding the length of the minor arc of the chord, finding the ratio of the radii of two given circles and whose arcs of the same lengths extend at a given angle, etc.

On solving the NCERT questions of the chapter you will be able to understand the terms like degree and radian measure, the notational convention of degree and radian, trigonometric functions, domain and range of trigonometric functions, trigonometric functions of sum of two angles and trigonometric equations. What makes our NCERT solutions for class 11 maths so unique is step-wise explanations and adherence to the latest CBSE syllabus.

Important Topics for NCERT Solutions for Class 11 Maths Chapter 3: Trigonometric Functions


NCERT Solutions for Class 11 Maths Chapter 3 talks about the Trigonometric Functions. Let us first understand what Trigonometry is. It is an important branch of maths concerned with the specific functions of angles and their application to calculations. The word Trigonometry is made from the two Greek-words namely Trigonon (triangle) and Metron (to measure).

Trigonometric Functions

Coming to the functions, there are mainly six functions of an angle, that relate a right angle to its sides. The names and abbreviations of the functions are Sine (sin), Cosine (cos), Tangent (tan), Cotangent (cot), Secant (sec), and Cosecant (cosec). To study these, we first need to understand what is an angle?

An angle is a space between the two intersecting lines or surfaces at or close to the point where they meet, and which is usually measured in degrees. In other words, it is the amount of rotation, performed from the initial side to the terminal side. On the basis of the side of rotations, we can divide an angle into two types – Positive Angle (when the line rotates in an anti-clockwise direction) and Negative Angle (when the lines rotate in a clockwise direction).


The next topic to be studied in this chapter is about Quadrants. When we rotate a line in the anti-clockwise direction, we divide an entire 360 degrees into four equal parts, thus making four quadrants namely – the first quadrant from 0-90 degree; second quadrant from 90-180 degree; third quadrant from 180-270 degree and fourth quadrant from 270-360 degree.

Methods of Measuring an Angle 

Further, this chapter includes various methods of measuring angles. These are the methods of measuring an angle- 

(i) Sexagesimal System (British System): In this system, the entire 90 degrees are further divided into 1 degree each. It is the first step in which we measure by degree. Another rule for this system is that if we divide the entire 90 degrees into 60 equal parts, then each part will represent one minute. So, we can conclude that 1 degree is equal to 60 minutes, and one minute is equal to 60 seconds. 

(ii) Centesimal System- In this system, we divide one degree into a hundred equal parts, and each part is equal to one grade. Again, one grade is divided into a hundred parts, and each part is called one minute, this one minute is equal to hundred seconds.

(iii) Radian System – It is also called the Circulatory System. In the end, this chapter also discusses the relationship between the radius and the number line.

Below are some of the most important tricks related to NCERT Class 11 Maths Chapter 3

  1. Since Trigonometry is all about the relation between triangles, so master your knowledge of Geometry first; 
  2. Try to focus specifically on the Right Angle triangles; 
  3. Study the Pythagorean Theorem very minutely and discuss with your subject teacher in case of any doubt; 
  4. Memorize the six Trigonometric functions and their relationships well; 
  5. Learn the three main things related to the Unit Circle, that are the conversions from degrees to radians, knowing the three ratios, how to use the unit circle and et al. 

Exercise-wise Discussion on NCERT Solutions for Class 11 Maths Chapter 3

  1. Exercise 3.1 has 7 questions that will increase your solving efficiency regarding trigonometric functions. 
  2. Exercise 3.2 comprises 10 questions related to values of trigonometry.  
  3. Exercise 3.3 has 25 questions that test your knowledge about the trigonometric concepts of the chapter.
  4. Exercise 3.4 has further 9 questions based on the solutions of the trigonometric equations. 

About NCERT Solutions for Class 11 Maths Chapter 3 by Instasolv

The NCERT solutions for class 11 maths chapter 3 offered by the experts at Instasolv are the best when it comes to a clear explanation of concepts related to trigonometric functions. Each question is solved step-wise so that you can understand the process and at the same time inculcate the habit of solving questions step-wise. This will help you in scoring better marks in the CBSE exams.