问题
解答题
计算与化简 (1)化简:
(2)计算:(3
(3)tan30°sin60°+cos230°-sin245°tan45°. |
答案
(1)原式=3
-2
-1-3 2 2
+2
-1=2
-2;3 2 2
(2)原式=(6
-3
+42 3 3
)÷23
=3-3
+2=41 3
;2 3
(3)原式=
×3 3
+3 2
-3 4
×1=1 2
+1 2
-3 4
=1 2
.3 4