已知cos（x-y）cosx+sin（x+y）sinx=m.且y为第三象限角,求siny?

cos（x+y）sinx-sin（x+y）cosx 已知Sin(x+y)Cosx-Cos(x-x)Sinx=3/5求tan2y的值 已知sin(x-y)cosx-cos(x-y)sinx=3/5求tan2y的值 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? 已知sin(x-y)cosx-cos(y-x)sinx=3分之5,y是第三象限角,求sin(y+5π分之4）的值 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 求y=sin(cosx)的导数.RT.已知f(x）=sin(cosx),求导. 已知cos（x-y）cosx+sin（x+y）sinx=m.且y为第三象限角,求siny? cos(x+y)-cosx如何等于-2sin[(2x+y)/2]sin(y/2), 已知sinx+siny=1/3,cosx-cosy=1/5,求cos(x+y),sin(x-y).求过程! 已知cos(x-y)cosx+sin(x-y)sinx=3/5,则cosy的值为 已知sin(x-y)cosx-cos(x-y)sinx=五分之三求tan2y的值