优优班--学霸训练营 > 知识点挑题
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            • 1.
              已知\(A\),\(B\),\(C\)是单位圆上不同的三点,\(O\)为坐标原点,若\(5 \overrightarrow{OA}+12 \overrightarrow{OB}+13 \overrightarrow{OC}= \overrightarrow{0}\),则\( \overrightarrow{OC}\cdot \overrightarrow{AB}=(\)  \()\)
              A.\( \dfrac {7}{13}\)
              B.\(- \dfrac {7}{13}\)
              C.\( \dfrac {12}{5}\)
              D.\(- \dfrac {12}{5}\)
            • 2.
              已知向量\( \overrightarrow{a}=(\cos x,\sin x)\),\( \overrightarrow{b}=(3,- \sqrt {3})\),\(x∈[0,π]\).
              \((1)\)若\( \overrightarrow{a}/\!/ \overrightarrow{b}\),求\(x\)的值;
              \((2)\)记\(f(x)= \overrightarrow{a}\cdot \overrightarrow{b}\),求\(f(x)\)的最大值和最小值以及对应的\(x\)的值.
            • 3.
              在\(\triangle ABC\),\(∠C=90^{\circ}\),\(AB=2BC=4\),\(M\),\(N\)是边\(AB\)上的两个动点,且\(|MN|=1\),则\( \overrightarrow{CM}\cdot \overrightarrow{CN}\)的取值范围为\((\)  \()\)
              A.\([ \dfrac {11}{4},9]\)
              B.\([5,9]\)
              C.\([ \dfrac {15}{4},9]\)
              D.\([ \dfrac {11}{4},5]\)
            • 4.
              已知向量\( \overrightarrow{a}, \overrightarrow{b}\)满足\(| \overrightarrow{a}|=1,| \overrightarrow{b}|=2, \overrightarrow{a}\)与\( \overrightarrow{b}\)的夹角为\(60^{\circ}\),则\(| \overrightarrow{a}-2 \overrightarrow{b}|=\) ______ .
            • 5.
              设\(F_{1}\)、\(F_{2}\)分别是椭圆\( \dfrac {x^{2}}{4}+y^{2}=1\)的左、右焦点.
              \((\)Ⅰ\()\)若\(P\)是第一象限内该椭圆上的一点,且\( \overrightarrow{PF_{1}}\cdot \overrightarrow{PF_{2}}=- \dfrac {5}{4}\),求点\(P\)的坐标;
              \((\)Ⅱ\()\)设过定点\(M(0,2)\)的直线\(l\)与椭圆交于不同的两点\(A\)、\(B\),且\(∠AOB\)为锐角\((\)其中\(O\)为坐标原点\()\),求直线\(l\)的斜率\(k\)的取值范围.
            • 6.
              设\(F_{1}\),\(F_{2}\)是双曲线\( \dfrac {x^{2}}{a^{2}}- \dfrac {y^{2}}{b^{2}}=1(a > 0,b > 0)\)的左、右两个焦点,若双曲线右支上存在一点\(P\),使\(( \overrightarrow{OP}+ \overrightarrow{OF_{2}})⋅ \overrightarrow{F_{2}P}=0(O\)为坐标原点\()\),且\(|PF_{1}|= \sqrt {3}|PF_{2}|\),则双曲线的离心率为\((\)  \()\)
              A.\( \dfrac { \sqrt {2}+1}{2}\)
              B.\( \sqrt {2}+1\)
              C.\( \dfrac { \sqrt {3}+1}{2}\)
              D.\( \sqrt {3}+1\)
            • 7.
              边长为\(2\)的等边\(\triangle ABC\)所在平面内一点\(M\)满足\( \overrightarrow{CM}= \dfrac {1}{3} \overrightarrow{CB}+ \dfrac {1}{2} \overrightarrow{CA}\),则\( \overrightarrow{MA}\cdot \overrightarrow{MB}=(\)  \()\)
              A.\(- \dfrac {8}{9}\)
              B.\(- \dfrac {4}{9}\)
              C.\( \dfrac {4}{9}\)
              D.\( \dfrac {8}{9}\)
            • 8.
              已知向量\( \overrightarrow{a}=(1,λ)\),\( \overrightarrow{b}=(3,1)\),若向量\(2 \overrightarrow{a}- \overrightarrow{b}\)与\( \overrightarrow{c}=(1,2)\)共线,则向量\( \overrightarrow{a}\)在向量\( \overrightarrow{c}\)方向上的投影为 ______ .
            • 9.
              已知\(\triangle ABC\)满足\( \overrightarrow{AB}^{2}= \overrightarrow{AB}\cdot \overrightarrow{AC}+ \overrightarrow{BA}\cdot \overrightarrow{BC}+ \overrightarrow{CA}\cdot \overrightarrow{CB}\),则\(\triangle ABC\)是\((\)  \()\)
              A.等边三角形
              B.锐角三角形
              C.直角三角形
              D.钝角三角形
            • 10.
              在平行四边形\(ABCD\)中,\(AB=4\),\( \overrightarrow{CP}=3 \overrightarrow{PD}\),若\( \overrightarrow{AB}\cdot \overrightarrow{BP}=-1\),则\( \overrightarrow{AB}\cdot \overrightarrow{AD}=\) ______ .
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