已知tanx,tany是方程x^2+6x+7=0的两个根,求证sin(x+y)=cos(x+y).
已知tanx,tany是方程x^2+6x+7=0的两个根,求证sin(x+y)=cos(x+y).
已知TanX,TanY是方程X^-3X-3=0的俩根,求sin^(x+y)-3sin(x+y)cos(x+y)-3cos
已知tanx,tany是方程x+6x+7=0的两个根,则tan(x+y) 已知cosθ=-1/2
已知tanx,tany是方程x平方+Px+Q=0的两个根求sin(x+y)平方+
已知sin(x+y)/cos(x-y)=m/n,则tanx/tany=?
tanX,tanY是方程X²+(4M+1)X+2M=0的俩根,且M≠-1/2求sin(X+Y)/cos(X-Y
求证tanx+tany/tanx-tany=sin(x+y)/sin(x-y)(详细步骤)
证明 (tanX+tanY)/(tanX-tanY)=(sin(X+Y))/(sin(X-Y))
已知sin(x+y)=1,求证:tan(2x+y)+tany=0
已知sin(x+y)=1,求证:tan(2x+y)+tany=0
已知sin(x+y)=1,求证:tan(2x+3y)=tany
sin(x+y)=1\2,sin(x—y)=1\3,求[tan(x+y)-tanx-tany]\[tany的平方tan(