xsinx cos2x
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¹ØÓÚÈý½Çº¯ÊýµÄת»» sin2x,cos2x,tan2x.ת»¯sinx,conx...
sin2x=2sinxcosx=¡À2sinx¡Ì(1-cos²x)cos2x=cos²x-sin²x=2cos²x-1tan2x=2tanx/(1-tan²x...
3.y=sinxcos2x, Çó y`
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