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Trig identity problem?
Can someone solve this step by step?
(sin x + sin3x)/ (cos x + cos 3x) = tan 2x
Show all your work and don't skip steps please. If you skip steps you will not be voted best answer.
- grunfeldLv 78 years agoFavorite Answer
LHS = ( sin x + sin 3x) / ( cos x + cos 3x )
LHS = 2 sin ( 2x) cos (x) / 2 cos (2x ) cos ( x )
LHS = tan 2x
LHS = RHS
QEDSource(s): my brain