Find the general solution of each of the following equations:

sin x + sin 3x + sin 5x = 0


To Find: General solution.


Given: sin x + sin 3x + sin 5x = 0 sin 3x + 2sin 3x cos 2x= 0 sin 3x (1 + 2cos 2x) = 0


[NOTE: sin C + sin D = 2sin (C+D)/2 × cos (C-D)/2]


sin 3x = 0 or cos 2x = = cos()


Formula used: sin= 0 = n , n I, cos = cos = 2k , k I


3x = n or 2x = 2k x = or x = k where n,k I


So general solution is x = or x = k where n, k, I


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