求证：sin(2x+y)/sinx-2cos(x+y)=siny/sinx(2)已知5siny=sin(2x+y),求证:tan(x+y)=3/2 tanx

求证sin（2x+y)/sinx-2cos(x+y)=siny/sinx 求证：sin(2x+y)/sinx-2cos(x+y)=siny/sinx 求证sinx+siny=2sin(x+y)/2*cos(x-y)/2 求证:sinx+siny=2sin(x+y)/2cos(x-y)/2 求证|sinx-siny|=|2sin[(x-y)/2]cos[(x+y)/2]| 3sinX=sin(2X+Y) 求证：tan(X+Y)=2tanX tan(x+y)=2tany,求证3sinx=sin(x+2y) 求证 sin^2x/(sinx-cosx)-(sinx+cosx)/tan^2 x-1=sinx+cosx y=sinx/sin^2x-sinx+2求最值 求证：sin(2x+y)/sinx-2cos(x+y)=siny/sinx(2)已知5siny=sin(2x+y),求证:tan(x+y)=3/2 tanx 求证sin^2x/sinx-cosx-(sinx+cosx)/(tan^2-1)=sinx+cosx谢谢GGJJ 求证sinx-cosx=根号2sin(x-π/4) 已知sinθ+cosθ=2sinx,sinθcosθ=sin²y,求证：4cos²2x=cos²2y sin(2x+y)/sinx-2cos(x+y) 化简 求函数的值域：(1)y=|sinx|-2sinx (2)y=sin|x| |sinx| 求函数的值域：(1)y=|sinx|-2sinx (2)y=sin|x|+|sinx| 求y=sin^2x+x/sinx的最小值 证明 [sin(2x+y)/sinx]-2cos(x+y)=siny/sinx