优优班--学霸训练营 > 知识点挑题
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            • 1.

              已知\(C:{{x}^{2}}+{{y}^{2}}-2x-4y-4=0\)与\(x\)轴交于\(A({x}_{1},0),B({x}_{2},0) \),与\(y\)轴交于\(C(0,{y}_{1}),D(0,{y}_{2}) \),则下列说法中不正确的是\((\)     \()\)

              A.\({{x}_{1}}+{{x}_{2}}=-2\)     
              B.\(|{{x}_{1}}-{{x}_{2}}|=2\sqrt{5}\)
              C.\({{y}_{1}}+{{y}_{2}}=4\)
              D.\({{x}_{1}}{{x}_{2}}={{y}_{1}}{{y}_{2}}\)
            • 2. \(10\)、圆心在直线\(x-2y+7=0\)上的圆\(C\)与\(x\)轴交于两点\(A(-2,0)\),\(B(-4,0)\),则圆\(C\)的方程为____________.

            • 3.

              过三点\(A(1,3)\),\(B(4,2)\),\(C(1,-7)\)的圆交于\(y\)轴于\(M\)、\(N\)两点,则\({S}_{∆AMN}= \)(    )

              A.  \( \sqrt{6} \)
              B.\(4\sqrt{6}\)
              C.\(8\sqrt{6}\)
              D.\(10\sqrt{6}\)
            • 4.
              若方程\(x^{2}+y^{2}-x+y+m=0\)表示圆,则实数\(m\)的取值范围是\((\)  \()\)
              A.\(m < \dfrac {1}{2}\)
              B.\(m > \dfrac {1}{2}\)
              C.\(m < 0\)
              D.\(m\leqslant \dfrac {1}{2}\)
            • 5.

              当\(a\)为任意实数时,直线\(\left( a-1 \right)x-y+a+1=0\)恒过定点\(C\),则以\(C\)为圆心,半径为\(\sqrt{5}\)的圆是\((\)    \()\)

              A.\({{x}^{2}}+{{y}^{2}}-2x+4y=0\)
              B.\({{x}^{2}}+{{y}^{2}}+2x+4y=0\)

              C.\({{x}^{2}}+{{y}^{2}}+2x-4y=0\)
              D.\({{x}^{2}}+{{y}^{2}}-2x-4y=0\)
            • 6.

              已知两点\(A(a,0)\),\(B(-a,0)(a > 0)\),若曲线\({{x}^{2}}+{{y}^{2}}-4\sqrt{3}x-4y+7=0\)上存在点\(P\),使得\(∠APB=90^{\circ}\),则正实数\(a\)的取值范围为\((\)    \()\)

              A.\((0,3]\)
              B.\([1,3]\)
              C.\([1,7]\)
              D.\([3,7]\)
            • 7.
              过原点\(O\)作圆\(x^{2}+y^{2}-6x-8y+20=0\)的两条切线,设切点分别为\(P\)、\(Q\),则线段\(PQ\)的长为___________.
            • 8.

              如图,在平面直角坐标系\(xOy\)中,已知以\(M\)为圆心的圆\(M:{{x}^{2}}+{{y}^{2}}-12x-14y+60=0\)及其上一点\(A\left( 2,4 \right)\).



              \((1)\)设圆\(N\)与\(x\)轴相切,与圆\(M\)外切,且圆心\(N\)在直线\(x=6\)上,求圆\(N\)的标准方程;

              \((2)\)设平行于\(OA\)的直线\(l\)与圆\(M\)相交于\(B,C\)两点,且\(BC=OA\),求直线\(l\)的方程;

              \((3)\)设点\(T(t,0)\)满足:存在圆\(M\)上的两点\(P\)和\(Q\),使得\(\overrightarrow{TA}+\overrightarrow{TP}=\overrightarrow{TQ},\),求实数\(t\)的取值范围.

            • 9.

              圆\({x}^{2}+{y}^{2}-4x=0 \)的圆心坐标为\((\)   \()\)

              A.\(\left(0,0\right) \)
              B.\(\left(2,0\right) \)
              C.\(\left(-2,0\right) \)
              D.\(\left(0,2\right) \)
            • 10. 若当方程\(x^{2}+y^{2}+kx+2y+k^{2}=0\)所表示的圆取得最大面积时,则直线\(y=(k-1)x+2\)的倾斜角\(α=(\)  \()\)
              A.\( \dfrac {3π}{4}\)
              B.\( \dfrac {π}{4}\)
              C.\( \dfrac {3π}{2}\)
              D.\( \dfrac {5π}{4}\)
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