> 数学 >
化简sin^4a-cos^4a/cos2a
人气:461 ℃ 时间:2020-05-23 17:58:16
解答
=(sin²a+cos²a) (sin²a-cos²a)/cos2a
= (sin²a-cos²a)/cos2a
=-cos2a/cos2a
=-1
推荐
猜你喜欢
© 2024 79432.Com All Rights Reserved.
电脑版|手机版