问题
解答题
计算: (1)cos45°-sin45°+sin30° (2)sin60°•cos30°+
|
答案
(1)原式=
-2 2
+2 2 1 2
=
;1 2
(2)原式=
×3 2
+3 2 1 4
=
+3 4 1 4
=1.
计算: (1)cos45°-sin45°+sin30° (2)sin60°•cos30°+
|
(1)原式=
-2 2
+2 2 1 2
=
;1 2
(2)原式=
×3 2
+3 2 1 4
=
+3 4 1 4
=1.