问题 解答题
计算:
(1)
2
(2cos45°-sin60°)+
24
4

(2)
2
sin45°+cos30°•tan60°-
(-3)2
答案

(1)

2
(2cos45°-sin60°)+
24
4

=

2
(2×
2
2
-
3
2
)+
24
4

=2-

6
2
+
6
2

=2.

(2)

2
sin45°+cos30°•tan60°-
(-3)2

=

2
×
2
2
+
3
2
×
3
-3

=1+

3
2
-3,

=-

1
2

判断题
单项选择题