化简sin (x+y)sin x +cos (x+y)cos x=

化简sin(2x-y)*sin y+cos(2x-y)*sin y sin(x.y)中, sin(x)^y求导 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) 求证sin²x-sin²y=sin(x+y)sin(x-y) 化简sin (x+y)sin x +cos (x+y)cos x= 化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x) 证明sin(x+y)sin(x-y)=sinx-siny y=sin根号x y=sinx+sin|x| sin(x+y)的导数 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 Mathematica y''+ sin(x) y=x