问题
填空题
若tanxtany=2,sinxsiny=
|
答案
由题意可得tanxtany=
=sinxsiny cosxcosy
=2,1 3cosxcosy
解得cosxcosy=
,故cos(x-y)=cosxcosy+sinxsiny=1 6
+1 6
=1 3
,1 2
故x-y=2kπ±
,k∈Zπ 3
故答案为:2kπ±
,k∈Zπ 3
若tanxtany=2,sinxsiny=
|
由题意可得tanxtany=
=sinxsiny cosxcosy
=2,1 3cosxcosy
解得cosxcosy=
,故cos(x-y)=cosxcosy+sinxsiny=1 6
+1 6
=1 3
,1 2
故x-y=2kπ±
,k∈Zπ 3
故答案为:2kπ±
,k∈Zπ 3