问题 解答题
计算:
sin60°+3tan30°•cos60°
(tan37°•tan53°-2cot45°)•cot30°
-
sin18°•sin90°
(sin212°+sin278°)cos72°
答案

原式=

3
2
+3×
3
3
×
1
2
(1-2×1)•
3
-1

=

3
2
+
3
2
-
3
-1

=

3
-
3
-1

=-1-1

=-2.

填空题
单项选择题