优优班--学霸训练营 > 知识点挑题
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            • 1.

              已知椭圆\(C:\dfrac{{{x}^{2}}}{3}+\dfrac{{{y}^{2}}}{{{b}^{2}}}=1\) \((b > 0)\)的左、右焦点分别为\({F}_{1},{F}_{2} \),直线\(AB\)过右焦点\({{F}_{2}}\),和椭圆\(C\)交于\(A,B\)两点,且满足\(\overrightarrow{A{{F}_{2}}}=2\overrightarrow{{{F}_{2}}B}\),\(\angle {{F}_{1}}AB={{90}^{0}}\),则椭圆\(C\)的离心率为(    )

              A.\(\dfrac{\sqrt{5}}{3}\)
              B.\(\dfrac{\sqrt{3}}{3}\)
              C.\(\dfrac{\sqrt{30}}{6}\)
              D.\(\dfrac{\sqrt{6}}{3}\)
            • 2.

              已知\(A\)、\(B\)、\(C\)为\(\triangle ABC\)的三个内角,向量\(m\)满足\(|m|=\dfrac{\sqrt{6}}{2}\),且\(m=(\sqrt{2}\sin \dfrac{B+C}{2},\cos \dfrac{B-C}{2})\),若\(A\)最大时,动点\(P\)使得\(|\overrightarrow{PB}|\)、\(|\overrightarrow{BC}|\)、\(|\overrightarrow{PC}|\)成等差数列,则\(\dfrac{|\overrightarrow{PA}|}{|\overrightarrow{BC}|}\)的最大值是

              A.\(\dfrac{2\sqrt{3}}{3}\)
              B.\(\dfrac{2\sqrt{2}}{3}\)
              C.\(\dfrac{\sqrt{2}}{4}\)
              D.\(\dfrac{3\sqrt{2}}{4}\)
            • 3.

              设椭圆\(C\):\(\dfrac{{x}^{2}}{{a}^{2}}+ \dfrac{{y}^{2}}{{b}^{2}}=1 (a > b > 0)\)的左、右焦点分别为\(F_{1}\)、\(F_{2}\),其焦距为\(2c\),点\(Q(c,\dfrac{a}{2} )\)在椭圆的内部,点\(P\)是椭圆\(C\)上的动点,且\(\left|P{F}_{1}\right|+\left|PQ\right| < 5\left|{F}_{1}{F}_{2}\right| \)恒成立,则椭圆离心率的取值范围是\((\)     \()\)


              A.\(\left( \dfrac{1}{5}, \dfrac{ \sqrt{2}}{5}\right) \)
              B.​\(\left( \dfrac{1}{4}, \dfrac{ \sqrt{2}}{2}\right) \)
              C.\(\left( \dfrac{1}{3}, \dfrac{ \sqrt{2}}{2}\right) \)
              D.\(\left( \dfrac{2}{5}, \dfrac{ \sqrt{2}}{2}\right) \)
            • 4.
              已知椭圆方程为\( \dfrac {x^{2}}{a^{2}}+ \dfrac {y^{2}}{b^{2}}=1(a > 0,b > 0)\),其右焦点为\(F(4,0)\),过点\(F\)的直线交椭圆与\(A\),\(B\)两点\(.\)若\(AB\)的中点坐标为\((1,-1)\),则椭圆的方程为\((\)  \()\)
              A.\( \dfrac {x^{2}}{45}+ \dfrac {y^{2}}{36}=1\)
              B.\( \dfrac {x^{2}}{12}+ \dfrac {y^{2}}{4}=1\)
              C.\( \dfrac {x^{2}}{24}+ \dfrac {y^{2}}{8}=1\)
              D.\( \dfrac {x^{2}}{18}+ \dfrac {y^{2}}{9}=1\)
            • 5.

              设\(F_{1}\),\(F_{2}\)分别为椭圆\(C_{1}\):\( \dfrac{{x}^{2}}{{a}^{2}}+ \dfrac{{y}^{2}}{{b}^{2}}=1 (a > b > 0)\)与双曲线\(C_{2}\):\( \dfrac{{x}^{2}}{{a}^{2}}- \dfrac{{y}^{2}}{{b}^{2}}=1 (a_{1} > 0,b_{1} > 0)\)的公共焦点,它们在第一象限内交于点\(M\),\(∠F_{1}MF_{2}=90^{\circ}\),若椭圆的离心率\(e= \dfrac{3}{4} \),则双曲线\(C_{2}\)的离心率\(e_{1}\)的值为

              A.\( \dfrac{9}{2} \)
              B.\( \dfrac{3 \sqrt{2}}{2} \)
              C.\( \dfrac{3}{2} \)
              D.\( \dfrac{5}{4} \)
            • 6.

              已知\(A,B,C\)为\(\Delta ABC\)的三个内角,向量\(\overrightarrow{m}\)满足\(|\overrightarrow{m}|=\dfrac{\sqrt{6}}{2}\),且\(\overrightarrow{m}=(\sqrt{2}\sin \dfrac{B+C}{2},\cos \dfrac{B-C}{2})\),若\(A\)最大时,动点\(P\)使得\(||\overrightarrow{PB}|,|\overrightarrow{BC}|,|\overrightarrow{PC}|\)成等差数列,则\(\dfrac{\overrightarrow{|PA|}}{\overrightarrow{|BC|}}\)的最大值是\((\)      \()\)

              A.\(\dfrac{2\sqrt{3}}{3}\)
              B.\(\dfrac{2\sqrt{2}}{3}\)
              C.\(\dfrac{\sqrt{2}}{4}\)
              D.\(\dfrac{3\sqrt{2}}{4}\)
            • 7.

              已知双曲线\(x^{2}-y^{2}=1\),点\(F_{1}\),\(F_{2}\)为其两个焦点,点\(P\)为双曲线上一点,若\(PF_{1}⊥PF_{2}\),则以\(F_{1}\),\(F_{2}\)为焦点且经过\(P\)的椭圆的离心率等于\((\)   \()\)

              A.\(\dfrac{\sqrt{5}}{5}\)
              B.\(\dfrac{\sqrt{6}}{3}\)
              C.\(\dfrac{\sqrt{2}}{2}\)
              D.\(\dfrac{1}{2}\)
            • 8. “a>0,b>0”是“方程ax2+by2=1表示椭圆”的(  )
              A.充要条件
              B.充分非必要条件
              C.必要非充分条件
              D.既不充分也不必要条件
            • 9. 已知椭圆的中心在坐标原点,焦点在x轴上,且短轴长为8,离心率为,则该椭圆的方程为(  )
              A.+=1
              B.+=1
              C.+=1
              D.+=1
            • 10.

              关于\(x\),\(y\)的方程\(y=mx+n\)和\(+\)\(=1\)在同一坐标系中的图象大致是(    )

              A.
              B.  
              C.
              D.
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