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Cos x + cos y formula
Ex 3.3, 11 Important
Misc 3
Misc 4 Important
Ex 3.3, 14
Ex 3.3, 15
Misc 5
Misc 7 Important
Example 16 Important
Ex 3.3, 16 Important You are here
Ex 3.3, 17
Ex 3.3, 18 Important
Ex 3.3, 19
Ex 3.3, 20
Ex 3.3, 21 Important
Example 17 Important
Misc 6 Important
cos x + cos y formula
Last updated at May 29, 2023 by Teachoo
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