问题 解答题
计算:(1)sin30°+cos45°+tan60°-cot30°;
(2)
sin263°-4cos60°sin63°+1
+cos27°+
cot30°-3tan30
sin30°-cos45°
答案

(1)原式=

1
2
+
2
2
+
3
-
3

=

1+
2
2

(2)原式=

sin263°-4×
1
2
sin63°+1
+cos27°+
cot30°-3tan30
sin30°-cos45°

=

sin263°-2sin63°+1
+cos27°+
cot30°-3tan30
sin30°-cos45°

=

(sin63°-1)2
+cos27°+
3
-3×
3
3
1
2
-
2
2

=1-sin63°+cos27°+0

=1.

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