已知tanx=
|
因为tanx=
,tan(x-y)=-1 2
,2 3
所以tan(2x-y)=tan[x+(x-y)]=
=tanx+tan(x-y) 1-tanxtan(x-y)
=-
-1 2 2 3 1+ 1 3
.1 8
故选A.
已知tanx=
|
因为tanx=
,tan(x-y)=-1 2
,2 3
所以tan(2x-y)=tan[x+(x-y)]=
=tanx+tan(x-y) 1-tanxtan(x-y)
=-
-1 2 2 3 1+ 1 3
.1 8
故选A.