题目
(2000•安徽)已知cosα<0.5,那么锐角α的取值范围是( )
A. 60°<α<90°
B. 0°<α<60°
C. 30°<α<90°
D. 0°<α<30°
A. 60°<α<90°
B. 0°<α<60°
C. 30°<α<90°
D. 0°<α<30°
提问时间:2021-03-02
答案
∵cos90°=0,cos60°=0.5,
又∵0<cosα<0.5,
∴60°<α<90°.
故选A.
又∵0<cosα<0.5,
∴60°<α<90°.
故选A.
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