优优班--学霸训练营 > 知识点挑题
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            • 1. 已知\(\triangle ABC\)是边长为\(3\)的等边三角形,点\(P\)是以\(A\)为圆心的单位圆上一动点,点\(Q\)满足\( \overrightarrow{AQ}= \dfrac {2}{3} \overrightarrow{AP}+ \dfrac {1}{3} \overrightarrow{AC}\),则\(| \overrightarrow{BQ}|\)的最小值是 ______ .
            • 2.

              如图,在平面四边形\(ABCD\)中,\(AB=2\),\(\triangle BCD\)是等边三角形,若\(\overrightarrow{AC}\cdot \overrightarrow{BD}=1\),则\(AD\)的长为        

            • 3. 在\(\triangle ABC\)中,\( \overrightarrow{AM}= \dfrac {1}{4} \overrightarrow{AB}+m⋅ \overrightarrow{AC}\),向量\( \overrightarrow{AM}\)的终点\(M\)在\(\triangle ABC\)的内部\((\)不含边界\()\),则实数\(m\)的取值范围是______.
            • 4.

              在\(\Delta ABC\)中,\(E\),\(F\)分别为\(AB,AC\)中点,\(P\)为\(EF\)上任意一点,实数\(x,y\)满足\(\overrightarrow{PA}+x\overrightarrow{PB}+y\overrightarrow{PC}=\overrightarrow{0}\),设\(\Delta ABC,\Delta PCA,\Delta PAB\)的面积分别为\(S\),\(S_{1}\),\(S_{2}\),记\( \dfrac{{S}_{1}}{S}={λ}_{1} \),\( \dfrac{{S}_{2}}{S}={λ}_{2} \),则\({λ}_{1},{λ}_{2} \)取得最大值时,\(2x+3y\)的值为 \((\)  \()\)

              A.\(-\dfrac{5}{2}\)
              B.\(\dfrac{5}{2}\)
              C.\(-\dfrac{3}{2}\)
              D.\(\dfrac{3}{2}\) 
            • 5.

              如图,在平行四边形\(ABCD\)中,\(E\)为\(DC\)的中点,\(AE\)与\(BD\)交于点\(M\),\(AB= \sqrt[]{2}\),\(AD=1\),且\(\overrightarrow{MA}·\overrightarrow{MB}=- \dfrac{1}{6}\),则\(\overrightarrow{AB}·\overrightarrow{AD}=\)_______

            • 6.

              已知椭圆\({C}_{1}\;:\; \dfrac{{x}^{2}}{{a}^{2}}+ \dfrac{{y}^{2}}{{b}^{2}}=1\left(a > b > 0\right) \) 经过点\(M\left(1, \dfrac{3}{2}\right) \),且其右焦点与抛物线\({C}_{2}\;:\;{y}^{2}=4x \)的焦点\(F\)重合,过点\(F\)且与坐标轴不垂直的直线与椭圆交于\(P\),\(Q\)两点.

              \((1)\)求椭圆\({C}_{1} \)的方程;

              \((2)\)设\(O\)为坐标原点,线段\(OF\)上是否存在点\(N\left(n,0\right) \),使得\( \overrightarrow{QP}· \overrightarrow{NP}= \overrightarrow{PQ}· \overrightarrow{NQ} \)?若存在,求出\(n\)的取值范围;若不存在,说明理由;

              \((3)\)过点\({P}_{0}\left(4,0\right) \)且不垂直于\(x\)轴的直线与椭圆交于\(A\),\(B\)两点,点\(B\)关于\(x\)轴的对称点为\(E\),试证明:直线\(AE\)过定点.

            • 7.

              \((\)本小题满分\(12\)分\()\)

              平面内给定三个向量\( \overrightarrow{a}=(3,2)\),\( \overrightarrow{b}=(-1,2)\),\( \overrightarrow{c}=(4,1)\)
              \((1)\)求\(3 \overrightarrow{a}+ \overrightarrow{b}-2 \overrightarrow{c}\);
              \((2)\)求满足\( \overrightarrow{a}=m \overrightarrow{b}+n \overrightarrow{c}\)的实数\(m\)、\(n\).

            • 8.

              已知\(O\)是\(\triangle ABC\)的外心,若\(AB=AC\),\(∠CAB=30^{\circ}\),且\( \overrightarrow{CO}={λ}_{1} \overrightarrow{CA}+{λ}_{2} \overrightarrow{CB} \),则\(λ_{1}λ_{2}=\)________.

            • 9.

              已知点\(G\)是边长为\(2\)的等边\(\triangle ABC\)的重心,点\(D\)是\(BC\)的中点,则\(\overrightarrow{CG}\cdot \overrightarrow{AD}=\) ________.

            • 10. 给出下列命题:
              \(①\)若\(\overset{→}{a}· \overset{→}{b}=0 \),则\(\overset{→}{a}⊥ \overset{→}{b} \);
              \(②\left| \overset{→}{a}+ \overset{→}{b}\right| > \left| \overset{→}{a}- \overset{→}{b}\right| \)
              \(③\)设\( \overset{→}{{e}_{1}}, \overset{→}{{e}_{2}} \)不共线,\( \overset{→}{{e}_{1}}+2 \overset{→}{{e}_{2}} \)与\( \overset{→}{{e}_{2}}+2 \overset{→}{{e}_{1}} \)能作为一组基底
              \(④\)若存在一个实数\(k\)满足\( \overset{→}{a}=k \overset{→}{b} \),则\( \overset{→}{a} \)与\( \overset{→}{b} \)共线,其中正确命题的个数是\((\)   \()\)                                


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