优优班--学霸训练营 > 知识点挑题
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            • 1. 如图,在正方形\(ABCD\)中,\(AB=2\),点\(E\),\(F\)分别在边\(AB\),\(DC\)上,\(M\)为\(AD\)的中点,且\(\overrightarrow{ME}· \overrightarrow{MF}=0 \)\(∆MEF \)的面积的取值范围为      \((\)  \()\)

              A.\(\left[1, \dfrac{5}{4}\right] \)
              B.\(\left[1,2\right] \)
              C.\(\left[ \dfrac{1}{2}, \dfrac{5}{4}\right] \)
              D.\(\left[ \dfrac{1}{2}, \dfrac{3}{2}\right] \)
            • 2.

              已知抛物线\(y=ax^{2}(a > 0)\)上两个动点\(A\)、\(B(\)不在原点\()\),满足\( \overset{⇀}{OA}⊥ \overset{⇀}{OB} \),若存在定点\(M\),使得\( \overset{⇀}{OM}=λ \overset{⇀}{OA}+μ \overset{⇀}{OB} \),且\(λ+μ=1\),则\(M\)坐标为           \((\)     \()\)

              A.\((\{0,-a\})\)    
              B.\((\{0,a\})\)  
              C.\(( \dfrac{1}{a} ,0\})\)     
              D.\((0, \dfrac{1}{a} )\)
            • 3.

              已知向量\(\overrightarrow{a}=(x,1),\overrightarrow{b}=(0,1)(x > 0)\),若向量\(2\overrightarrow{a}-\overrightarrow{b}\)与\(\overrightarrow{a}-2\overrightarrow{b}\)垂直,则\(x=\)_________.

            • 4.

              在平面直角坐标系\(xOy\)中,抛物线\({{y}^{2}}=2px\left( p > 0 \right)\)的焦点为\(F\),点\(A(4,m)\)在抛物线上,且\(|AF|=5\).

              \((1)\)求抛物线的标准方程.

              \((2)\)直线\(l\)过点\((0,1)\),并与抛物线交于\(B\),\(C\)两点,满足\(\overrightarrow{OB}\cdot \overrightarrow{OC}=0\),求出直线\(l\)的方程

            • 5.

              已知两个不共线的向量\(\overrightarrow{a}\) ,\(\overrightarrow{b}\) 的夹角为\(θ\),且\(|\overrightarrow{a}|=3\) ,\(|\overrightarrow{b}|=1\) ,\(x\)为正实数.

              \((1)\)若\(\overrightarrow{a}+2\overrightarrow{b}\) 与\(\overrightarrow{a}-4\overrightarrow{b}\) 垂直,求\(\tan θ\);

              \((2)\)若\(\theta =\dfrac{\pi }{6}\) ,求\(|x\overrightarrow{a}-\overrightarrow{b}|\) 的最小值及对应的\(x\)的值,并指出向量\(\overrightarrow{a}\) 与\(x\overrightarrow{a}-\overrightarrow{b}\) 的位置关系;

              \((3)\)若\(θ\)为锐角,对于正实数\(m\),关于\(x\)的方程\(|x\overrightarrow{a}-\overrightarrow{b}|=|m\overrightarrow{a}|\) 有两个不同的正实数解,且\(x\neq m\),求\(m\)的取值范围.

            • 6.

              在平面直角坐标系中,\(i\)\(j\)分别是与\(x\)轴、\(y\)轴正方向同向的单位向量,\(O\)为坐标原点\(.\)设向量\(=2\)\(i\)\(+\)\(j\),\(=3\)\(i\)\(+\)\(kj\),若\(⊥\),则实数\(k\)的值为

              A.\(6\) 
              B.\(-6\)  
              C.\(1\)  
              D.\(-1\)
            • 7.

              已知非零向量\(m\),\(n\)满足\(3|m|=2|n|\),\( < m\),\(n > =60^{\circ}\),若\(n⊥(tm+n)\)则实数\(t\)的值为

              A.\(3\)
              B.\(-3\)
              C.\(2\)
              D.\(-2\)
            • 8.

              已知\(P\)是双曲线\( \dfrac{x^{2}}{a^{2}}- \dfrac{y^{2}}{b^{2}}=1(a > 0,b > 0)\)上的点,\(F_{1}\),\(F_{2}\)是其焦点,双曲线的离心率是\( \dfrac{5}{4}\),且\(\overrightarrow{P{{F}_{{1}}}}·\overrightarrow{P{{F}_{{2}}}}=0\),若\(\triangle PF_{1}F_{2}\)的面积为\(9\),则\(a+b\)的值为\((\)  \()\)

              A.\(5\)                                                    
              B.\(6\)

              C.\(8\)                                                      
              D.\(7\)
            • 9.

              \((1)\)已知\(a\),\(b\),\(c\)分别是\(\triangle ABC\)的三个内角\(A\),\(B\),\(C\)的对边,若\(a=1\),\(b=\sqrt{3}\),\(A+C=2B\),则\(\sin C=\)________.

              \((2)\)若实数\(x\),\(y\)满足不等式组\(\begin{cases} & x+3y-3\geqslant 0 \\ & 2x-y-3\leqslant 0 \\ & x-y+1\geqslant 0 \\ \end{cases}\)则\(x+y\)的最大值为________.

              \((3)\)若\(|\overrightarrow{a}|=1\),\(|\overrightarrow{b}|=2\),\(\overrightarrow{c}=\overrightarrow{a}+\overrightarrow{b}\),且\(\overrightarrow{a}\bot \overrightarrow{c}\),则向量\(\overrightarrow{a}\)与\(\overrightarrow{b}\)的夹角为________.

              \((4)\)观察下列各式:

              \(a+b=1\),\(a^{2}+b^{2}=3\),\(a^{3}+b^{3}=4\),\(a^{4}+b^{4}=7\),\(a^{5}+b^{5}=11\),\(……\),则\(a^{10}+b^{10}=\)

            • 10.

              \(x\)\(y\)\(∈R\),向量\(a\)\(=(\)\(x\),\(1)\),\(b\)\(=(1,\)\(y\)\()\),\(c\)\(=(2,-4)\)且\(a\)\(⊥\)\(c\)\(b\)\(/\!/\)\(c\),则\(|\)\(a\)\(+\)\(b\)\(|=(\) \()\)


              A.\(跱B勃盱{\)
              B.\(跱B勃盱{\)
              C.\(2跱B勃盱{\)     
              D.\(10\)
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