问题
解答题
计算下列各题. (1)sin230°+cos245°+
(2)tan2°•tan4°•tan6°…tan88°. |
答案
(1)原式=
+1 4
+2 4
×2
×1=3 2
+3 4
;6 2
(2)原式=tan2°•tan4°•tan6°•cot6°•cot4°•cot2°,
=(tan2°•cot2°)(tan4°•cot4°)•(tan6°•cot6°),
=1
计算下列各题. (1)sin230°+cos245°+
(2)tan2°•tan4°•tan6°…tan88°. |
(1)原式=
+1 4
+2 4
×2
×1=3 2
+3 4
;6 2
(2)原式=tan2°•tan4°•tan6°•cot6°•cot4°•cot2°,
=(tan2°•cot2°)(tan4°•cot4°)•(tan6°•cot6°),
=1