求化简过程,亲!

2025-05-06 15:50:38
推荐回答(2个)
回答1:

解:
(sin²25°-1/2)/sin40°
=(2sin²25°-1)/2sin40°
=-cos50°/2sin40°
=-sin40°/2sin40°
=-1/2

回答2:


请采纳