优优班--学霸训练营 > 知识点挑题
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            • 1.
              已知椭圆\(E\):\( \dfrac {x^{2}}{a^{2}}+ \dfrac {y^{2}}{b^{2}}=1(a > b > 0)\)的右焦点为\(F\),短轴的一个端点为\(M\),直线\(l\):\(3x-4y=0\)交椭圆\(E\)于\(A\),\(B\)两点,若\(|AF|+|BF|=4\),点\(M\)到直线\(l\)的距离不小于\( \dfrac {4}{5}\),则椭圆\(E\)的离心率的取值范围是\((\)  \()\)
              A.\((0, \dfrac { \sqrt {3}}{2}]\)
              B.\((0, \dfrac {3}{4}]\)
              C.\([ \dfrac { \sqrt {3}}{2},1)\)
              D.\([ \dfrac {3}{4},1)\)
            • 2.

              已知圆\(O\)的方程为\(x^{2}+y^{2}=9\),若抛物线\(C\)过点\(A(-1,0)\),\(B(1,0)\),且以圆\(O\)的切线为准线,则抛物线\(C\)的焦点\(F\)的轨迹方程为    \((\)  \()\)

              A.\(\dfrac{x^{2}}{9}-\dfrac{y^{2}}{8}=1\left( x{\neq }0 \right)\)
              B.\(\dfrac{x^{2}}{9}+\dfrac{y^{2}}{8}=1\left( x{\neq }0 \right)\)
              C.\(\dfrac{x^{2}}{9}-\dfrac{y^{2}}{8}=1\left( y{\neq }0 \right)\)
              D.\(\dfrac{x^{2}}{9}+\dfrac{y^{2}}{8}=1\left( y{\neq }0 \right)\)
            • 3.

              已知椭圆\(E:\dfrac{{{x}^{2}}}{{{a}^{2}}}+\dfrac{{{y}^{2}}}{{{b}^{2}}}=1\left( a > b > 0 \right)\)的右焦点为\(F\left( 3,0 \right)\),过点\(F\)的直线交\(E\)于\(A,B\)两点,若\(AB\)的中点坐标为\(\left( 1,-1 \right)\),则\(E\)的方程为  \((\)   \()\)

              A.\(\dfrac{{{x}^{2}}}{45}+\dfrac{{{y}^{2}}}{36}=1\)
              B.\(\dfrac{{{x}^{2}}}{36}+\dfrac{{{y}^{2}}}{27}=1\)
              C.\(\dfrac{{{x}^{2}}}{27}+\dfrac{{{y}^{2}}}{18}=1\)
              D.\(\dfrac{{{x}^{2}}}{18}+\dfrac{{{y}^{2}}}{9}=1\)
            • 4.

              已知椭圆\(C\):\( \dfrac{x^{2}}{a^{2}}+ \dfrac{y^{2}}{b^{2}}=1(a > b > 0)\)的离心率为\( \dfrac{1}{2}\),以原点为圆心,椭圆的短半轴长为半径的圆与直线\(x-y+ \sqrt{6}=0\)相切,则椭圆\(C\)的方程为\((\)  \()\)

              A.\( \dfrac{x^{2}}{8}+ \dfrac{y^{2}}{6}=1\)          
              B.\( \dfrac{x^{2}}{12}+ \dfrac{y^{2}}{9}=1\)

              C.\( \dfrac{x^{2}}{4}+ \dfrac{y^{2}}{3}=1\)          
              D.\( \dfrac{x^{2}}{6}+ \dfrac{y^{2}}{4}=1\)
            • 5.

              已知椭圆\( \dfrac{x^{2}}{25}+ \dfrac{y^{2}}{m^{2}}=1(\)\(m\)\( > 0)\)的左焦点为\(F\)\({\,\!}_{1}(-4,0)\),则\(m\)\(=(\)  \()\)

              A.\(2\)        
              B.\(3\)        
              C.\(4\)            
              D.\(9\)
            • 6.
              已知直线\(x-2y+4=0\)经过椭圆\( \dfrac {x^{2}}{a^{2}}+ \dfrac {y^{2}}{b^{2}}=1(a > b > 0)\)的顶点和焦点,则椭圆的标准方程为\((\)  \()\)
              A.\( \dfrac {x^{2}}{20}+ \dfrac {y^{2}}{16}=1\)
              B.\( \dfrac {x^{2}}{20}+ \dfrac {y^{2}}{4}=1\)
              C.\( \dfrac {x^{2}}{16}+ \dfrac {y^{2}}{12}=1\)
              D.\( \dfrac {x^{2}}{16}+ \dfrac {y^{2}}{4}=1\)
            • 7.

              如果\({{x}^{2}}+k{{y}^{2}}=2\)表示焦点在\(y\)轴上的椭圆,那么实数\(k\)的取值范围是\((\)    \()\)

              A.\(\left( 0,+\infty \right)\)
              B.\(\left( 0,2 \right)\)
              C.\(\left( 1,+\infty \right)\)
              D.\(\left( 0,1 \right)\)
            • 8.

              以椭圆\(\dfrac{{{x}^{2}}}{25}+\dfrac{{{y}^{2}}}{16}=1\)的顶点为顶点,离心率为\(2\)的双曲线方程为  

              A.\(\dfrac{{{y}^{2}}}{16}-\dfrac{{{x}^{2}}}{48}=1\)
              B.\(\dfrac{{{x}^{2}}}{25}-\dfrac{{{y}^{2}}}{75}=1\) 

              C.\(\dfrac{{{y}^{2}}}{16}-\dfrac{{{x}^{2}}}{48}=1\)或\(\dfrac{{{x}^{2}}}{25}-\dfrac{{{y}^{2}}}{75}=1\)
              D.以上都不对
            • 9.

              已知\(P\)是以\({{F}_{1}}{{,}_{{}}}{{F}_{2}}\)为焦点的椭圆上一点,经过焦点\({{F}_{2}}\)作\(\angle {{F}_{1}}P{{F}_{2}}\)外角平分线的垂线,则垂足\(M\)的轨迹是

              A.抛物线
              B.双曲线
              C.椭圆
              D.圆
            • 10.

              如果方程\( \dfrac{{x}^{2}}{{a}^{2}} + \dfrac{{y}^{2}}{a+6} =1\)表示焦点在\(x\)轴上的椭圆,则实数\(a\)的取值范围是(    ).

              A.\(a\)\( > 3\)    
              B.\(a\)\( < -2\)   
              C.\(a\)\( > 3\)或 \(a\)\( < -2\)       
              D.\(a\)\( > 3\)或\(-6 < \) \(a\)\( < -2\)
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