cos150°×cos(-570°)×tan(-330°)/cos(-420°)×sin(-690°)

来源：学生作业帮助网 编辑：作业帮 时间：2024/05/07 22:01:38
cos150°×cos(-570°)×tan(-330°)/cos(-420°)×sin(-690°)

cos150°×cos(-570°)×tan(-330°)/cos(-420°)×sin(-690°)
cos150°×cos(-570°)×tan(-330°)/cos(-420°)×sin(-690°)

cos150°×cos(-570°)×tan(-330°)/cos(-420°)×sin(-690°)
cos150°×cos(-570°)×tan(-330°)/cos(-420°)×sin(-690°)
=-cos30°×cos210°×tan(-30°)/cos60°×sin30°
=-√3/2×（-√3/2）×（-√3/3）/（1/2×1/2）
=3/4×（-√3/3）×4=-√3