已知：3sinY=sin(2X+Y),求证tan(X+Y)=2tanX

已知x-y=派/3,且sin x-siny=1/2,求cos(x+y). siny=1/3,sin(x＋y)=1,求sin(2x＋y) 已知(sinx)2-(siny)2=m求sin(x y)sin(x-y)求sin(x+y)sin(x-y) 已知：3sinY=sin(2X+Y),求证tan(X+Y)=2tanX 已知5siny=sin(2x+y),求证:tan(x+y)=3/2tanx 已知sinx+siny=1/3,cosx-cosy=1/5,求cos(x+y),sin(x-y).求过程! 已知xy-sin(πy^2)=0 x^2y+siny^2=0求y的一阶导数 已知sinx-siny=1/2,cosx-cosy=1/2,x、y均为锐角,求sin(x-y) 已知cos(x+y)cosy+sin(x+y)siny=4/5,求tanx的值 sinx+siny=-1/3 cosx+cosy=1/2,求sin(x+y)的值. 已知sin(2x+y)=5siny,(y不等于K派),求证;3tan=2tan(x+y) 已知x,y,z属于(0,派/2),sin^2x+sin^2y+sin^2z=1,求(sinx+siny+sinz)/(cosx+cosy+cosz)的最大值 已知sinx-siny=-2/3,cosx-cosy=2/3,x,y为锐角,求sin(x+y)的值为1 已知sin(2x-y)5/13,siny=-3/5,x属于（派/2,派),y属于(-派/2,0),求sinx的值 求解一道三角函数体已知sin(2x+y)=5siny,求证2tan(x+y)=3tanx. 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 求函数z=sinx+siny+sin(x+y)(0 求推导sinx-siny=2cos（(x+y)/2)sin((x-y)/2)