问题
解答题
计算:(1)tan30°cot60°+cos230°-sin245°tan45° (2)(
|
答案
(1)tan30°cot60°+cos230°-sin245°tan45°
=
×3 3
+(3 3
)2-(3 2
)2×12 2
=
+1 3
-3 4 1 2
=
;7 12
(2)(
)-1+(2-1 2
)0-23
cos60°+2 1
+12
=2+1-2
×2
+1 2
-12
=2.