问题 填空题
tanxtany=2,sinxsiny=
1
3
,则x-y=______.
答案

由题意可得tanxtany=

sinxsiny
cosxcosy
=
1
3cosxcosy
=2,

解得cosxcosy=

1
6
,故cos(x-y)=cosxcosy+sinxsiny=
1
6
+
1
3
=
1
2

故x-y=2kπ±

π
3
,k∈Z

故答案为:2kπ±

π
3
,k∈Z

判断题
单项选择题 A1型题