来自董志宏的问题
【求证:1−2sin2xcos2xcos22x−sin22x=1−tan2x1+tan2x.】
求证:1−2sin2xcos2xcos22x−sin22x=1−tan2x1+tan2x.
1回答
2020-01-31 16:37
【求证:1−2sin2xcos2xcos22x−sin22x=1−tan2x1+tan2x.】
求证:1−2sin2xcos2xcos22x−sin22x=1−tan2x1+tan2x.
证明:左边=cos