优优班--学霸训练营 > 知识点挑题
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            • 1.

              已知抛物线\(y^{2}=4x\),焦点为\(F\),过点\(F\)作直线\(l\)交抛物线于\(A\),\(B\)两点,则\(|AF|-\dfrac{2}{\mathrm{{|}}{BF}\mathrm{{|}}}\)的最小值为  \((\)  \()\)

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

              直线\(l\)与抛物线\(y^{2}=2px\)只有一个公共点,则\(l\)与抛物线相切\(.(\)  \()\)

              A.正确

              B.错误
            • 3.

              已知抛物线\(C:{y}^{2}=2px(p > 0) \)的焦点为\(F\),\(M(3,2)\),直线\(MF\)交抛物线于\(A\),\(B\)两点,且\(M\)为\(AB\)的中点,则\(p\)的值为(    )

              A.\(3\)               
              B.\(2\)或\(4\)           
              C.\(4\)               
              D.\(2\)
            • 4.

              已知\(F\)为抛物线\(C: y^{2}=4x\)的焦点,过\(F\)的直线\(l\)与\(C\)相交于\(A\),\(B\)两点,线段\(AB\)的垂直平分线交\(x\)轴于点\(M\),垂足为\(E\),若\(\left| {AB} \right|=6\),则\(\left| {EM} \right|= (\)  \()\)

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

              已知抛物线\(y^{2}=4x\)的焦点为\(F\),过焦点\(F\)的直线交该抛物线于\(A\),\(B\)两点,\(O\)为坐标原点,若\(\triangle AOB\)的面积为\( \sqrt{6}\),则\(|AB|=(\)  \()\)

              A.\(6\)                                                             
              B.\(8\)

              C.\(12\)                                                           
              D.\(16\)
            • 6.
              抛物线\(y=2{{x}^{2}}\)上两点\(A({{x}_{1}},{{y}_{1}})\)、\(B({{x}_{2}},{{y}_{2}})\)关于直线\(y=x+m\)对称,且\({{x}_{1}}\cdot {{x}_{2}}=-\dfrac{1}{2}\),则\(m\)等于\((\)    \()\)

              A.\(\dfrac{3}{2}\)
              B.\(2\)
              C.\(\dfrac{5}{2}\)
              D.\(3\)
            • 7.

              过点\(N(0,-1)\)作直线\(l\)与抛物线\(y^{2}=x\)相交于\(A\),\(B\)两点,\(M\)为弦\(AB\)的中点,\(P(4,1)\)为定点,且\(M\)与\(P\)不重合,求直线\(PM\)在\(y\)轴上的截距\(b\)的取值范围\((\)   \()\)

              A.\((0,1)\)
              B.\((0,+∞)\)
              C.\((0,\dfrac{1}{3})\bigcup (\dfrac{1}{3},1)\bigcup (1,+\infty )\)
              D.\((\dfrac{1}{3},+\infty )\)
            • 8.

              过抛物线\({{y}^{2}}=4x\)的焦点作直线交该抛物线于\(A({{x}_{1}},{{y}_{1}}),B({{x}_{2}},{{y}_{2}})\)两点,如果\({{x}_{1}}+{{x}_{2}}=6\),则\(|AB|\)等于(    )

              A.\(4\)          
              B.\(6\)       
              C.\(8\)    
              D.\(10\)
            • 9.

              过点\(M\)\((3,2)\)作直线\(l\)与抛物线\(y\)\({\,\!}^{2}=8\)\(x\)只有一个交点,这样的直线共有(    )


              A.\(0\)条      
              B.\(1\)条        
              C.\(2\)条       
              D.\(3\)条
            • 10.

              过点\(M(\dfrac{\sqrt{2}}{2},-\dfrac{\sqrt{2}}{2})\)作圆\({{x}^{2}}+{{y}^{2}}=1\)的切线\(l\),\(l\)与\(x\)轴的交点为抛物线\(E:{{y}^{2}}=2px(p > 0)\)的焦点,\(l\)与抛物线\(E\)交于\(A,B\)两点,则\(AB\)中点到抛物线\(E\)的准线的距离为\((\)     \()\)

              A.\(4\sqrt{2}\)        
              B.\(3\sqrt{2}\)
              C.\(\dfrac{7\sqrt{2}}{2}\)
              D.\(\dfrac{5\sqrt{2}}{2}\)
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