Class 10 Maths Exercise 8.3 Question 4 | Introduction to Trigonometry | NCERT Solutions

In this video, we solve NCERT Class 10 Mathematics – Chapter 8 (Introduction to Trigonometry), Exercise 8.3, Question 4. Question. 4 Prove the following identities, where the angles involved are acute angles for which the expressions are defined: 0:00 Problem 1 (i). (cosec θ − cot θ)² = (1 − cos θ) / (1 + cos θ) 2:02 Problem 2 (ii). cos A / (1 + sin A) + (1 + sin A) / cos A = 2 sec A 4:34 Problem 3 (iii). tan θ / (1 − cot θ) + cot θ / (1 − tan θ) = 1 + sec θ cosec θ 9:14 Problem 4 (iv). (1 + sec A) / sec A = sin² A / (1 − cos A) 11:16 Problem 5 (v). (cos A − sin A + 1) / (cos A + sin A − 1) = cosec A + cot A 15:17 Problem 6 (vi). √[(1 + sin A) / (1 − sin A)] = sec A + tan A 17:12 Problem 7 (vii). (sin θ − 2 sin³ θ) / (2 cos³ θ − cos θ) = tan θ 19:23 Problem 8 (viii). (sin A + cosec A)² + (cos A + sec A)² = 7 + tan² A + cot² A 22:16 Problem 9 (ix). (cosec A − sin A)(sec A − cos A) = 1 / (tan A + cot A) 24:56 Problem 10 (x). (1 + tan² A) / (1 + cot² A) = (1 − tan A)² / (1 − cot A)² = tan² A REFERENCE Question 4 – Step by Step Solution https://arjunschool.com/ncert-solutio... [Android App] NCERT Books Download Manager (Free) https://play.google.com/store/apps/de... More Resources: NCERT Books – https://arjunschool.com/ncert-books NCERT Solutions – https://arjunschool.com/ncert-solutions NCERT Exemplar Solutions – https://arjunschool.com/ncert-exemplar