问题 解答题
计算:(1)tan30°cot60°+cos230°-sin245°tan45°
(2)(
1
2
)-1+(2-
3
)0-2
2
cos60°+
1
2
+1
答案

(1)tan30°cot60°+cos230°-sin245°tan45°

=

3
3
×
3
3
+(
3
2
2-(
2
2
2×1

=

1
3
+
3
4
-
1
2

=

7
12

(2)(

1
2
)-1+(2-
3
)0-2
2
cos60°+
1
2
+1

=2+1-2

2
×
1
2
+
2
-1

=2.

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