1.sin(90°+33°)为什么=cos33°?2.sin63°sin123°+cos117°sin33°=?
问题描述:
1.sin(90°+33°)为什么=cos33°?2.sin63°sin123°+cos117°sin33°=?
答
1.sin(90°+33°)为什么=cos33°?2.sin63°sin123°+cos117°sin33°=?