题目内容
cot+cot+cot·cot等于
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A.tan<cot B.tan>cot C.sin<cos D.sin>cos
A.sinθ<cosθ<cotθ
B.cosθ<cotθ<sinθ
C.cotθ<sinθ<cosθ
D.cosθ<sinθ<cotθ
①sin(kπ+α)=(-1)k·sinα;②cos(kπ+α)=(-1)k·cosα;③tan(kπ+α)=(-1)k·tanα;④cot(kπ+α)=(-1)k·cotα
A.1 B.2 C. 3D.4