问题
解答题
求值:sin245°-cos60°+tan60°•cos230°.
答案
原式=(
)2-2 2
+1 2
×(3
)2,3 2
=
-1 2
+1 2 3 4
,3
=3 4
.3
求值:sin245°-cos60°+tan60°•cos230°.
原式=(
)2-2 2
+1 2
×(3
)2,3 2
=
-1 2
+1 2 3 4
,3
=3 4
.3