4.thanks.

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/05/16 06:16:15

解题思路：先把角设出来，然后利用两角和差公式求出
解题过程：
.

Thanks ,thanks! thanks! 英语画谜 thanks thanks thanks thanks thanks thanks thanks thanks 帮看下 thanks thanks thanks given thanks our 有一首歌歌词有句是 thanks thanks thanks monica Many thanks 帮看下 thanks! 6,thanks. please,thanks Thanks(选择)