sin(x+y)cosx+cos(x+y)sinx=1/3 x∈(3π/2,2π) 求cos(2x+π/4)

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 化简cos(x+y)sinx-sin(x+y)cosx sinx*sin(x+y)+cosx*cos(x+y)等于? cos（x+y）sinx-sin（x+y）cosx y= sin x cos x+sinx+cosx的值域 Y= SIN X - COS X / 2 COSX 的导数Y= SIN X - COS X / 2 COSX 的导数 cos(x+y)*cos(x-y)=cos*cosx+sin*siny cos(x+y)-cosx如何等于-2sin[(2x+y)/2]sin(y/2), 证明sinx+cos(x+y)siny/cosx-sin(x+y)siny=tan(x+y) 证明cosx-cos(x+2y)/2siny= sin(x+y)证明cosX-cos(x+2y)/2siny= sin(x+y) 为什么y=sinx,y=-sin(-x)=sinx,y=cosx,y=-cos(-x)=-cosx 请问怎么证明sinX+sin(X+Y)+sin(X+2Y)/cosX+cos(X+Y)+cos(X+2Y)=tan(X+Y), 求y=|cosx| y=|tanx| y=sin|x| y=cos|x| y=tan|x|周期 已知sin(x-y)cosx-cos(x-y)sinx=3/5求tan2y的值 若cos(x+y)cosy+sin(x+y)siny=0,则cosx= 已知Sin(x+y)Cosx-Cos(x-x)Sinx=3/5求tan2y的值