问题
解答题
计算: (1)
(2)2cos30°-2sin30°+5tan60°; (3)
(4)tan230°+2sin60°cos45°+tan45°-tan30°-cos230°. |
答案
(1)原式=
-11 2
-23
=
;2+ 3 2
(2)原式=2×
-2×3 2
+51 2 3
=6
-1;3
(3)原式=
+3 4
+1 2 3 4
=
;
+13 2
(4)原式=
+1 3
×3
+1-2 2
-3 3 3 4
=
.6
-46
+73 12