已知tanx=4/3,x在(π,3/2π),若tany=1/2,求证 cos(x-y)=2sin(x-y)
已知sin(x+y)=1,求证:tan(2x+3y)=tany
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=2,tany=3,x,y∈(0,π/2),求x+y.
若sin(x+y)=1/2,sin(x-y)=1/3,则tanx/tany等于?
sin(x+y)=1\2,sin(x—y)=1\3,求[tan(x+y)-tanx-tany]\[tany的平方tan(
若x、y是锐角且tanx=2/3tany=3/4则sin(x+y)等于
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)/cos(x-y)=m/n,则tanx/tany=?
cos(x+y)=1/5,cos(x-y)=3/5则tanx.tany=?
求证tanx+tany/tanx-tany=sin(x+y)/sin(x-y)(详细步骤)