题文
角
顶点在坐标原点O,始边

轴的非负半轴重合,点P在

的终边上,点

,且

夹角的余弦值为( )A.

B.

C.

D.

题型:未知 难度:其他题型
答案

解析
由题意,设角
终边上点

的坐标为

,所以

选

.
考点
据考高分专家说,试题“角顶点在坐标原点O,始边轴的非负半轴重合.....”主要考查你对 [向量数量积的含义及几何意义 ]考点的理解。
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