tan(3x)證明

3tanx-tan^3x
—————— = tan3X
1-3tan^2x

這是證明題
tan2x+tanx
———————- <=Tan (2x+x) <= Tan3x
1-(tan2x)(tanx)

Tan^3X = 3 power of Tanx <=== 忘了中文怎講 抱歉..

 

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