三角函数公式.求解,谢谢
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三角函数公式.求解,谢谢
![三角函数公式.求解,谢谢](/uploads/image/z/19867699-19-9.jpg?t=%E4%B8%89%E8%A7%92%E5%87%BD%E6%95%B0%E5%85%AC%E5%BC%8F.%E6%B1%82%E8%A7%A3%2C%E8%B0%A2%E8%B0%A2)
喂,图在哪里?还是想列写三角公式啊
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再答: sin(x+y)=sinxcosy-cosxsiny��sin2x=2sinxcosx; cos(x+y)=cosxcosy-sinxsiny;cos2x=2(cosx)^2-1 sin2x+sin2y=2sin(x+y)cos(x-y) sin2x-sin2y=2cos(x+y)sin(x-y) cos2x+cos2y=2cos(x+y)cos(x-y) cos2x-cos2y=-2sin(x+y)sin(x-y) 2sin2xcos2y=sin(x+y)cos(x-y) ̫���ˡ�������������������
再问: ��ǹ�ʽ�������
再答: sin(x+y)=sinxcosy-cosxsiny��sin2x=2sinxcosx; cos(x+y)=cosxcosy-sinxsiny;cos2x=2(cosx)^2-1 sin2x+sin2y=2sin(x+y)cos(x-y) sin2x-sin2y=2cos(x+y)sin(x-y) cos2x+cos2y=2cos(x+y)cos(x-y) cos2x-cos2y=-2sin(x+y)sin(x-y) 2sin2xcos2y=sin(x+y)cos(x-y) ̫���ˡ�������������������