题目内容
计算:(1)sin30°+cos45°+tan60°-cot30°;
(2)
+cos27°+
.
(2)
| sin263°-4cos60°sin63°+1 |
| cot30°-3tan30 |
| sin30°-cos45° |
(1)原式=
+
+
-
=
;
(2)原式=
+cos27°+
=
+cos27°+
=
+cos27°+
=1-sin63°+cos27°+0
=1.
| 1 |
| 2 |
| ||
| 2 |
| 3 |
| 3 |
=
1+
| ||
| 2 |
(2)原式=
sin263°-4×
|
| cot30°-3tan30 |
| sin30°-cos45° |
=
| sin263°-2sin63°+1 |
| cot30°-3tan30 |
| sin30°-cos45° |
=
| (sin63°-1)2 |
| ||||||
|
=1-sin63°+cos27°+0
=1.
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