## trig identity

no clue how to start this:

show

sin 3x = 3 sin x - 4 sin^3 x
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 How to start this: sin(3x) = sin(2x+x)
 right so after doing this i get sin 3x = sin2x(cos x) + (cos2x)(sin x) whats next

## trig identity

sin(2x)=...?
cos(2x)=...?
 thanks for the help i got this and the others

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