Sin2x-tanx=? Complete the identity?

2 Answers
Feb 23, 2018

#tan xcos2x#

Explanation:

There may be different identities.
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Feb 23, 2018

tan x.cos 2x

Explanation:

#f(x) = sin 2x - tan x = 2sin x.cos x - sin x/(cos x)#
#f(x) = [2sin x.cos^2 x - sin x]/(cos x)#
#f(x) = [sin x(2cos^2 x - 1)]/(cos x)#
Note that
#2cos^2 x - 1 = cos 2x#
Therefor:
#f(x) = (sin x.cos 2x)/(cos x) = tan x.cos 2x#