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Last updated at Dec. 8, 2016 by Teachoo

Transcript

Ex 3.3, 16 Prove that 9 5 /( 17 3 ) = 2 / 10 Taking L.H.S 9 5 /( 17 3 ) We solve cos 9x cos 5x & sin 17x sin 3x seperately Now, 9 5 /( 17 3 ) = ( 2 sin (7x) sin (2x) )/(2 (10x)sin (7x) ) = sin (2x) / (10x) = R.H.S So, L.H.S. = R.H.S. Hence proved

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.