问题
选择题
角θ的顶点与坐标原点重合，始边与x轴非负半轴重合，终边经过点（
|
答案
∵角θ的终边经过点（
，1 2
）（始边与x轴非负半轴重合），3 2
∴cosθ=
=1 2 (
)2+(1 2
)23 2
．1 2
故选B．
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角θ的顶点与坐标原点重合，始边与x轴非负半轴重合，终边经过点（
|
∵角θ的终边经过点（
，1 2
）（始边与x轴非负半轴重合），3 2
∴cosθ=
=1 2 (
)2+(1 2
)23 2
．1 2
故选B．
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