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

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? cos（x+y）sinx-sin（x+y）cosx 已知Sin(x+y)Cosx-Cos(x-x)Sinx=3/5求tan2y的值 y= sin x cos x+sinx+cosx的值域 cos(x+y)*cos(x-y)=cos*cosx+sin*siny Y= SIN X - COS X / 2 COSX 的导数Y= SIN X - COS X / 2 COSX 的导数 cos(x+y)-cosx如何等于-2sin[(2x+y)/2]sin(y/2), 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 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 证明sinx+cos(x+y)siny/cosx-sin(x+y)siny=tan(x+y) 已知函数y=sin平方x+2sinx·cosx+3cos平方 求y的取值范围