Ex 3.3, 9 - Chapter 3 Class 11 Trigonometric Functions

Last updated at Dec. 13, 2024 by Teachoo

Ex 3.3, 9 - Prove cos (3pi/2+x) cos (2pi + x)[cot (3pi/2 - x) - Ex 3.3

part 2 - Ex 3.3, 9 - Ex 3.3 - Serial order wise - Chapter 3 Class 11 Trigonometric Functions

part 3 - Ex 3.3, 9 - Ex 3.3 - Serial order wise - Chapter 3 Class 11 Trigonometric Functions

Next: Ex 3.3, 10 → Remove Ads

Transcript

Ex 3.3, 9 Prove cos (3π/2+𝑥) cos (2π + 𝑥)[cot (3π/2−𝑥) + cot (2π + 𝑥)] =1 Solving L.H.S. Now, cos (𝟑𝝅/𝟐 "+ " 𝒙) = sin x cos (2π + x) = cos x cot (2π + x) = cot x cot (𝟑𝝅/𝟐−𝒙) = tan x Now putting values in equation cos (3π/2+𝑥) cos (2π + 𝑥)[cot (3π/2−𝑥) + cot (2π + 𝑥)] = (sin x) × (cos x) × [tan x + cot x] = (sin x cos x) × [cot x + tan x] = (sin x cos x) × [𝒄𝒐𝒔⁡𝒙/𝒔𝒊𝒏⁡𝒙 + 𝒔𝒊𝒏⁡𝒙/𝒄𝒐𝒔⁡𝒙 ] = (sin x cos x) × [(〖(cos〗⁡𝑥) × 〖(cos〗⁡𝑥)+〖 (sin〗⁡𝑥) × 〖(sin〗⁡𝑥))/(sin⁡𝑥 × 〖(cos〗⁡𝑥))] = (sin x cos x) × [(𝐜𝐨𝐬𝟐⁡𝒙 +〖 𝐬𝐢𝐧𝟐〗⁡𝒙)/(𝒔𝒊𝒏⁡𝒙 × 〖(𝒄𝒐𝒔〗⁡𝒙))] = cos2⁡𝑥 +〖 sin2〗⁡𝑥 = 1 = R.H.S Hence proved

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo

Class 6

Class 7

Class 8

Class 9

Class 10

Class 11

Class 12

Courses

Interesting

Popular