Example 21 - Solve cos x = 1/2 - Trigonometric Functions CBSE

Example 21 - Chapter 3 Class 11 Trigonometric Functions - Part 2

This video is only available for Teachoo black users

Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class


Transcript

Question 4 Solve cos 𝑥 = 1/2 Let cos x = cos y Given cos x = 1/2 From (1) and (2) cos y = 1/2 cos y = cos 𝜋/3 y = 𝜋/3 Rough We know that cos 60° = 1/2 So, 60° = 60 × π/180 = π/3 Since cos x = cos y General Solution is x = 2nπ ± y where n ∈ Z Putting y = 𝜋/3 x = 2nπ ±𝝅/𝟑 where n ∈ Z

Ask a doubt
Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.