问题
解答题
计算: (1)(1-sin60°+cos60°)(sin90°+cos60°-cos30°); (2)
|
答案
(1)原式=(1-
+3 2
)(1+1 2
-1 2
)=3-3 2 3 2
;3
(2)原式=
-1
-2 2 1 2
+2 2 1 2
=(
-1)2-12
=2-2
.2
计算: (1)(1-sin60°+cos60°)(sin90°+cos60°-cos30°); (2)
|
(1)原式=(1-
+3 2
)(1+1 2
-1 2
)=3-3 2 3 2
;3
(2)原式=
-1
-2 2 1 2
+2 2 1 2
=(
-1)2-12
=2-2
.2