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Last updated at May 30, 2018 by Teachoo

Transcript

cos x + cos y = 2 cos (x+y)/2 cos (x -y)/2 cos x - cos y = - 2 sin (x+y)/2 sin (x -y)/2 sin x + sin y = 2 sin (x+y)/2 cos (x -y)/2 sin x - sin y = 2 cos (x+y)/2 sin (x -y)/2

Cos x + cos y formula

Chapter 3 Class 11 Trigonometric Functions

Concept wise

- Radian measure - Conversion
- Arc length
- Finding Value of trignometric functions, given other functions
- Finding Value of trignometric functions, given angle
- (x + y) formula
- 2x 3x formula - Proving
- 2x 3x formula - Finding value
- cos x + cos y formula
- 2 sin x sin y formula
- Finding Principal solutions
- Finding General Solutions
- Sine and Cosine Formula

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.