优优班--学霸训练营 > 知识点挑题
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            • 1.

              已知\(O\) 是坐标原点,点\(A\)在第二象限,\(|\overrightarrow{OA}|=2\),\(∠xOA=150^{\circ}\),求向量\(\overrightarrow{OA}\)的坐标为               

            • 2.

              已知三个向量\(\overrightarrow{a},\overrightarrow{b},\overrightarrow{c}\)共面,且均为单位向量,\(\overrightarrow{a}\cdot \overrightarrow{b}=0\),则\(\left| \overrightarrow{a}+\overrightarrow{b}-\overrightarrow{c} \right|\)的取值范围是(    )

              A.\([\sqrt{2}-1,\sqrt{2}+1]\)
              B.\([1,\sqrt{2}]\)
              C.\([\sqrt{2}-1,1]\)
              D.\([\sqrt{2},\sqrt{3}]\)
            • 3.
              如图,正四面体\(ABCD\)的棱长为\(1\),点\(E\)是棱\(CD\)的中点,则\( \overrightarrow{AE}⋅ \overrightarrow{AB}=(\)  \()\)
              A.\(- \dfrac {1}{4}\)
              B.\(- \dfrac {1}{2}\)
              C.\( \dfrac {1}{4}\)
              D.\( \dfrac {1}{2}\)
            • 4.
              若\( \overrightarrow{OA}= \overrightarrow{a}\),\( \overrightarrow{OB}= \overrightarrow{b}\),\( \overrightarrow{a}\)与\( \overrightarrow{b}\)不共线,则\(∠AOB\)平分线上的向量\( \overrightarrow{OM}\)为\((\)  \()\)
              A.\( \dfrac { \overrightarrow{a}}{| \overrightarrow{a}|}+ \dfrac { \overrightarrow{b}}{| \overrightarrow{b}|}\)
              B.\( \dfrac { \overrightarrow{a}+ \overrightarrow{b}}{| \overrightarrow{a}+ \overrightarrow{b}|}\)
              C.\( \dfrac {| \overrightarrow{b}| \overrightarrow{a}-| \overrightarrow{a}| \overrightarrow{b}}{| \overrightarrow{a}|+| \overrightarrow{b}|}\)
              D.\(λ( \dfrac { \overrightarrow{a}}{| \overrightarrow{a}|}+ \dfrac { \overrightarrow{b}}{| \overrightarrow{b}|})\),\(λ\)由\( \overrightarrow{OM}\)确定
            • 5.
              向量\( \overrightarrow{a}\),\( \overrightarrow{b}\),\( \overrightarrow{c}\)在正方形网络中的位置如图所示,若\( \overrightarrow{c}=λ \overrightarrow{a}+μ \overrightarrow{b}(λ,μ∈R)\),则\( \dfrac {λ}{\mu }=(\)  \()\)
              A.\(-8\)
              B.\(-4\)
              C.\(4\)
              D.\(2\)
            • 6.
              如图,平行四边形\(OADB\)的对角线\(OD\)、\(AB\)相交于点\(C\),线段\(BC\)上有一点\(M\)满足\(BC=3BM\),线段\(CD\)上有一点\(N\)满足\(CD=3CN\),设\( \overrightarrow{OA}=a\),\( \overrightarrow{OB}=b\),试用\(a\),\(b\)表示\( \overrightarrow{OM}\),\( \overrightarrow{ON}\),\( \overrightarrow{MN}\).
            • 7.

              如图,已知\(AB\)是圆\(O\)的直径,点\(C\)、\(D\)是半圆弧的两个三等分点,\( \overrightarrow{AB}= \overrightarrow{a}, \overrightarrow{AC}= \overrightarrow{b},则 \overrightarrow{AD}= \)(    )


              A.\( \overset{→}{a}- \dfrac{1}{2} \overset{→}{b} \)
              B.\( \dfrac{1}{2} \overset{→}{a}- \overset{→}{b} \)
              C.\( \overset{→}{a}+ \dfrac{1}{2} \overset{→}{b} \)
              D.\( \dfrac{1}{2} \overset{→}{a}+ \overset{→}{b} \)
            • 8.

              在直角梯形\(ABCD\)中,\(AB/\!/CD\),\(AD\bot AB\),\(\angle B={{45}^{0}}AB=2=2CD\),\(M\)为腰\(BC\)上的中点,则\(\overrightarrow{MA}\cdot \overrightarrow{MD}\)值为   \((\)  \()\)


              A.\(1\)
              B.\(2\)
              C.\(3\)
              D.\(4\)
            • 9.

              如图,\(A,B \)分别是射线\(OM,ON \)上的两点,给出下列向量:\(① \overrightarrow{OA}+2 \overrightarrow{OB} \);\(② \dfrac{1}{2} \overrightarrow{OA}+ \dfrac{1}{3} \overrightarrow{OB} \);\(③ \dfrac{3}{4} \overrightarrow{OA}+ \dfrac{1}{3} \overrightarrow{OB} \);\(④ \dfrac{3}{4} \overrightarrow{OA}+ \dfrac{1}{5} \overrightarrow{OB} \);\(⑤ \dfrac{3}{4} \overrightarrow{OA}- \dfrac{1}{5} \overrightarrow{OB} \)。若这些向量均以\(O \)为起点,则终点落在阴影区域内\((\)包括边界\()\)的有\((\)   \()\)



              A.\(①②\)      
              B.\(②④\)      
              C.\(①③\)      
              D.\(③⑤\)
            • 10. 在\(\triangle ABC\)中,\(a\),\(b\),\(c\)分别为\(∠A\)、\(∠B\)、\(∠C\)、的对边,若向量\( \overrightarrow{m}=(a-b,1)\)和\( \overrightarrow{n}=(b-c,1)\)平行,且\(\sin B= \dfrac {4}{5}\),当\(\triangle ABC\)的面积为\( \dfrac {3}{2}\)时,则\(b=(\)  \()\)
              A.\( \dfrac {1+ \sqrt {3}}{2}\)
              B.\(2\)
              C.\(4\)
              D.\(2+ \sqrt {3}\)
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