已知tanx=1/2,tany=1/3,且x,y都是锐角,求证x+y=45°
已知x,y,z都是锐角,sin^2x+sin^2y+sin^2z=1,求tanx*tany*tanz的最值
若x、y是锐角且tanx=2/3tany=3/4则sin(x+y)等于
已知tanx=-3/4,且tan(x+y)=1,求tany的值
已知tanx=2,tany=1/3,则tan2(x+y)=
已知sin(x+y)=1,求证:tan(2x+3y)=tany
已知tanx=2,tany=3,x,y∈(0,π/2),求x+y.
已知tanx=1/4,tany=-3,求tan(x+y)的值
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
sin(x+y)=1\2,sin(x—y)=1\3,求[tan(x+y)-tanx-tany]\[tany的平方tan(
求证tanx+tany/tanx-tany=sin(x+y)/sin(x-y)(详细步骤)
cos(x+y)=1/5,cos(x-y)=3/5则tanx.tany=?