问题
解答题
计算下列各题: (1)sin230°+cos245°+
(2)
|
答案
(1)原式=(
)2+(1 2
)2+2 2
×2
×13 2
=
+1 4
+1 2 6 2
=
+3 4 1 2
;6
(2)原式=2
-4×3
+13 2
=2
-23
+13
=1.
计算下列各题: (1)sin230°+cos245°+
(2)
|
(1)原式=(
)2+(1 2
)2+2 2
×2
×13 2
=
+1 4
+1 2 6 2
=
+3 4 1 2
;6
(2)原式=2
-4×3
+13 2
=2
-23
+13
=1.