How do you verify sin3x/sin2x=2cosx-1/2secx?

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Answer 1 · 2018-03-10T02:20:49

As proved.

#(sin 3x) /( 2 sin x cos x) = 2 cos x - 1 /( 2 cos x)#

#sin 3x = 3 sin x - 4 sin^3x#

#:. (3 sin x - 4 sin^3x) / (2 sin x cos x)#

#(cancel (sin x) (3 - 4 sin ^2 x)) / (cancel (sin x) 2 cos x)#

#(3 - 4 + 4 cos^2x) / (2 cos x)#

#2 cos x - (1 / (2 cos x)) #

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