Ex 3.3

Ex 3.3, 1
Important

Ex 3.3, 2 Important

Ex 3.3, 3 Important

Ex 3.3, 4

Ex 3.3, 5 (i) Important

Ex 3.3, 5 (ii)

Ex 3.3, 6 Important

Ex 3.3, 7

Ex 3.3, 8 Important

Ex 3.3, 9 Important

Ex 3.3, 10

Ex 3.3, 11 Important

Ex 3.3, 12

Ex 3.3, 13 Important

Ex 3.3, 14

Ex 3.3, 15 You are here

Ex 3.3, 16 Important

Ex 3.3, 17

Ex 3.3, 18 Important

Ex 3.3, 19

Ex 3.3, 20

Ex 3.3, 21 Important

Ex 3.3, 22 Important

Ex 3.3, 23 Important

Ex 3.3, 24

Ex 3.3, 25

Chapter 3 Class 11 Trigonometric Functions

Serial order wise

Last updated at April 16, 2024 by Teachoo

Ex 3.3, 15 Prove that cot 4x (sin 5x + sin 3x) = cot x (sin 5x – sin 3x) Solving L.H.S. cot 4x (sin 5x + sin 3x) = cot 4x × [ 2 sin ((5𝑥 + 3𝑥)/2) cos ((5𝑥 − 3𝑥)/2) ] = cot 4x × [ 2sin (8𝑥/2) cos (2𝑥/2)] = 2 cot 4x sin 4x cos x = 2 𝑐𝑜𝑠4𝑥/𝑠𝑖𝑛4𝑥 × sin 4x × cos x = 2 cos 4x cos x Solving R.H.S. cot x (sin 5x – sin 3x) = cot x ( 2 cos (5𝑥 + 3𝑥)/2 sin (5𝑥 − 3𝑥)/2 ) = cot x ( 2 cos (8𝑥/2) sin (2𝑥/2)] = cot x ( 2 cos 4x sin x) = 2 cos 4x sin x cot x = 2 cos 4x sin x × 𝑐𝑜𝑠𝑥/sin𝑥 = 2 cos 4x cos x = L.H.S Hence L.H.S. = R.H.S. Hence Proved