化简sin(x+y)cos(x-y)+cos(x+y)sin(x-y)

化简sin(x+y)sin(x-y)-cos(x+y)cos(x-y)的结果是? 化简sin(x+y)cos(x-y)+cos(x+y)sin(x-y) 化简sin(2x-y)*sin y+cos(2x-y)*sin y 化简sin (x+y)sin x +cos (x+y)cos x= 化简sin(x+y)sinx+cos(x+y)cosx 化简sin(x+y)sinx+cos(x+y)cosx等于? 化简cos(x+y)sinx-sin(x+y)cosx sin(2x+y)/sinx-2cos(x+y) 化简 化简cos(x+y)sinx-sin(x+y)cosx 化简sin(x+y)sin(x-y)+cos(x+y)cos(x-y)除了展开,有简便算法么? sin(x-y)sin(x+y)-cos(x-y)cos(x+y) 化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x) y=(sin x + COS x)^2 化简y=(cos x)^2+sin x -2 谢谢 化简y=sin^4x-cos^4x, y=sin^2x+sinxcoswx+cos^2x 化简 请问sin（x+y）cos y-cos（x+y）sin y得多少 y=2cos x (sin x+cos x)