计算:(1)tan30°cot60°+cos230°-sin245°tan45°(2)(12)-1+(2-3)0-22cos60°+12+1.-数学

题目简介

计算:(1)tan30°cot60°+cos230°-sin245°tan45°(2)(12)-1+(2-3)0-22cos60°+12+1.-数学

题目详情

计算:(1)tan30°cot60°+cos230°-sin245°tan45°
(2)(
1
2
)-1+(2-
3
)0-2
2
cos60°+
1
2
+1
题型:解答题难度:中档来源:不详

答案

(1)tan30°cot60°+cos230°-sin245°tan45°
=
3
3
×
3
3
+(
3
2
)2-(
2
2
)2×1
=class="stub"1
3
+class="stub"3
4
-class="stub"1
2

=class="stub"7
12


(2)(class="stub"1
2
)-1+(2-
3
)0-2
2
cos60°+class="stub"1
2
+1

=2+1-2
2
×class="stub"1
2
+
2
-1
=2.

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