问题
解答题
计算:(1)sin30°+cos45°+tan60°-cot30°; (2)
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答案
(1)原式=
+1 2
+2 2
-3 3
=
;1+ 2 2
(2)原式=
+cos27°+sin263°-4×
sin63°+11 2 cot30°-3tan30 sin30°-cos45°
=
+cos27°+sin263°-2sin63°+1 cot30°-3tan30 sin30°-cos45°
=
+cos27°+(sin63°-1)2
-3×3 3 3
-1 2 2 2
=1-sin63°+cos27°+0
=1.