周大生铂金手镯图片:请问和差化积,积化和差是什么啊?

来源:百度文库 编辑:高考问答 时间:2024/07/05 23:24:05

和差化积 sinX+sinY=2sin[(X+Y)/2]cos[(X-Y)/2];
sinX-sinY=2cos[(X+Y)/2]sin[(X-Y)/2]
cosX+cosY=2cos[(X+Y)/2]cos[(X-Y)/2]
cosX-cosY=-2sin[X+Y)/2]sin[(X-Y)/2]

积化和差sinXcosY=1/2[sin(X+Y)+sin(X-Y)]
cosXsinY=1/2[sin(X+Y)-sin(X-Y)]