Table of Contents

myCBSEguide App

Download the app to get CBSE Sample Papers 2024-25, NCERT Solutions (Revised), Most Important Questions, Previous Year Question Bank, Mock Tests, and Detailed Notes.

Install Now

CBSE class 10 Mathematics Chapter 8 Introduction to Trigonometry notes in PDF are available for free download in myCBSEguide mobile app. The best app for CBSE students now provides Introduction to Trigonometry class 10 Notes latest chapter wise notes for quick preparation of CBSE board exams and school based annual examinations. Class 10 Mathematics notes on Chapter 8 Introduction to Trigonometry are also available for download in CBSE Guide website.

CBSE Guide Introduction to Trigonometry class 10 Notes

CBSE guide notes are the comprehensive notes which covers the latest syllabus of CBSE and NCERT. It includes all the topics given in NCERT class 10 Mathematics text book. Users can download CBSE guide quick revision notes from myCBSEguide mobile app and my CBSE guide website.

10 Mathematics notes Chapter 8 Introduction to Trigonometry

Download CBSE class 10th revision notes for Chapter 8 Introduction to Trigonometry in PDF format for free. Download revision notes for Introduction to Trigonometry class 10 Notes and score high in exams. These are the Introduction to Trigonometry class 10 Notes prepared by team of expert teachers. The revision notes help you revise the whole chapter in minutes. Revising notes in exam days is on of the the best tips recommended by teachers during exam days.

Download Revision Notes as PDF

CBSE Class 10 MATHEMATICS
Revision Notes
CHAPTER 8
INTRODUCTION TO TRIGONOMETRY

Trigonometry literally means measurement of sides and angles of a triangle.
Positive and Negative angles: Angles in anti-clockwise direction are taken as positive angles and angles in clockwise direction are taken as negative angles.
Trigonometric Ratios of an acute angle of a right angled triangle:

In a right triangle ABC, right-angled at B,
$sin A = \frac{{side{\text{ }}opposite{\text{ }}to{\text{ }}angle{\text{ }}A}}{{hypotenuse}}$
$cos A = \frac{{side{\text{ }}opposite{\text{ }}to{\text{ }}angle{\text{ }}A}}{{hypotenuse}}$
$\tan \,A = \frac{{side{\text{ }}opposite{\text{ }}to{\text{ }}angle{\text{ }}A}}{{side\,adjacent\,to\,angle\,A}}$
$\cot {\rm{A}} = {{{\rm{Hypotenuse}}} \over {{\rm{Side opposite to angle A}}}}$
$\sec {\rm{A}} = {{{\rm{Hypotenuse}}} \over {{\rm{Side adjacent to angle A}}}}$

$\cos ec\,A = \frac{1}{{\sin \,A}}; \ \ \ \sec A = \frac{1}{{\cos \,A}}$

$\tan \,A = \frac{1}{{\cot \,A}},\ \ \ \ \tan \,A = \frac{{\sin \,A}}{{\cos \,A}}$

$\cot {\rm{A}} = {1 \over {{\rm{tan A}}}}$ , $\cot {\rm{A}} = {{\cos {\rm{A}}} \over {\sin {\rm{A}}}}$

If one of the trigonometric ratios of an acute angle is known, the remaining trigonometric ratios of the angle can be easily determined.

(a) Find the sides of the right triangle in terms of k.

(b) Use Pythagoras Theorem and find the third side of the right triangle.

(d) k is cancelled from numerator and denominator and the value of t-ratio is obtained.

Trigonometric Ratios of some specified angles:

The values of trigonometric ratios for angles 0°, 30°, 45°, 60° and 90°.

Angle A	0^o	30^o	45^o	60^o	90^o
sin A	0	${1 \over 2}$	${1 \over {\sqrt 2 }}$	${{\sqrt 3 } \over 2}$	1
cos A	1	${{\sqrt 3 } \over 2}$	${1 \over {\sqrt 2 }}$	${1 \over 2}$	0
tan A	0	${1 \over {\sqrt 3 }}$	1	$\sqrt 3$	$\infty$
cot A	$\infty$	$\sqrt 3$	1	${1 \over {\sqrt 3 }}$	0
cosec A	$\infty$	2	$\sqrt 2$	${2 \over {\sqrt 3 }}$	1
Sec A	1	${2 \over {\sqrt 3 }}$	$\sqrt 2$	2	$\infty$

The value of sin A or cos A never exceeds 1, whereas the value of sec A or cosec A is always greater than or equal to 1.
Trigonometric Ratios of Complementary Angles:

sin(90° – A) = cos A, cos(90° – A) = sinA;

tan (90° – A) = cot A, cot (90° – A) = tan A;

sec (90° – A) = cosec A, cosec (90° – A) = sec A.

Trigonometric Identities:

${\sin ^2}{\rm{A}} + {\cos ^2}{\rm{A}} = 1$

${\sec ^2}{\rm{A}} - {\tan ^2}{\rm{A}} = 1$ for 0° ≤ A < 90°,

$\cos e{c^2}{\rm{A}} - {\cot ^2}{\rm{A}} = 1$ for 0° < A ≤ 90°.

Introduction to Trigonometry class 10 Notes

CBSE Revision notes (PDF Download) Free
CBSE Revision notes for Class 10 Mathematics PDF
CBSE Revision notes Class 10 Mathematics – CBSE
CBSE Revisions notes and Key Points Class 10 Mathematics
Summary of the NCERT books all chapters in Mathematics class 10
Short notes for CBSE class 10th Mathematics
Key notes and chapter summary of Mathematics class 10
Quick revision notes for CBSE board exams

CBSE Class-10 Revision Notes and Key Points

Introduction to Trigonometry class 10 Notes. CBSE quick revision note for Class-10 Mathematics, Chemistry, Maths, Biology and other subject are very helpful to revise the whole syllabus during exam days. The revision notes covers all important formulas and concepts given in the chapter. Even if you wish to have an overview of a chapter, quick revision notes are here to do if for you. These notes will certainly save your time during stressful exam days.

To download Introduction to Trigonometry class 10 Notes, sample paper for class 10 Mathematics, Social Science, Science, English Communicative; do check myCBSEguide app or website. myCBSEguide provides sample papers with solution, test papers for chapter-wise practice, NCERT solutions, NCERT Exemplar solutions, quick revision notes for ready reference, CBSE guess papers and CBSE important question papers. Sample Paper all are made available through the best app for CBSE students and myCBSEguide website.

Test Generator

Create question paper PDF and online tests with your own name & logo in minutes.

Create Now

myCBSEguide

Question Bank, Mock Tests, Exam Papers, NCERT Solutions, Sample Papers, Notes