优优班--学霸训练营 > 知识点挑题
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            • 1. 直线\(3x+4y=b\)与圆\(x^{2}+y^{2}-2x-2y+1=0\)相切,则\(b=(\)  \()\)
              A.\(-2\)或\(12\)
              B.\(2\)或\(-12\)
              C.\(-2\)或\(-12\)
              D.\(2\)或\(12\)
            • 2. 已知点\(P\left( x,y \right)\)是直线\(kx+y+4=0\left( k > 0 \right)\)上的一动点,\(PA,PB\)是圆\(C:{{x}^{2}}+{{y}^{2}}-2y=0\)的两条切线\((C\)为圆心\()\),\(A,B\)是切点,若四边形\(PACB\)的面积的最小值是\(2\),则\(k\)的值为\((\)     \()\)
              A.\(3\)
              B.\(\dfrac{\sqrt{21}}{2}\)
              C.\(2\sqrt{2}\)
              D.\(2\)
            • 3.

              过点\(P(2{,}4)\)作圆\(C\):\((x{-}1)^{2}{+}(y{-}2)^{2}{=}5\)的切线,则切线方程为\((\)   \()\)

              A.\(\sqrt{3}x{-}y{=}0\)
              B.\(2x{-}y{=}0\)     
              C.\(x{+}2y{-}10{=}0\)
              D.\(x{-}2y{-}8{=}0\)
            • 4.

              若过点\(P(1,\sqrt{3})\)作圆\(O\):\(x^{2}+y^{2}=1\)的两条切线,切点分别为\(A\)、\(B\)两点,则\(|AB|=\)________.

            • 5.

              如图,椭圆\(C:\dfrac{{{x}^{2}}}{{{a}^{2}}}+\dfrac{{{y}^{2}}}{{{b}^{2}}}=1(a > b > 0)\)的离心率为\(\dfrac{1}{2}\),过椭圆\(C\)上异于顶点的任一点\(P\)作圆\(O:{{x}^{2}}+{{y}^{2}}={{b}^{2}}\)的两条切线,切点分别为\(A,B\),若直线\(AB\)与\(x,y\)轴分别交于\(M,N\)两点,则\(\dfrac{{{b}^{2}}}{|OM{{|}^{2}}}+\dfrac{{{a}^{2}}}{|ON{{|}^{2}}}\)的值为(    )

              A.\(1\)
              B.\(\dfrac{5}{3}\)
              C.\(\dfrac{3}{2}\)
              D.\(\dfrac{4}{3}\)
            • 6.

              \((1)\)已知扇形的周长是\(4cm\),面积是\(1cm^{2}\),则扇形的圆心角的弧度数是________.

              \((2)\)圆\(x^{2}+y^{2}-4x=0\)在点\(P(2,2)\)处的切线方程为:________.

              \((3)\)在三棱锥\(P—ABC\)中,\(D\),\(E\)分别是\(PB\),\(PC\)的中点,记三棱锥\(D—ABE\)的体积为\(V_{1}\),\(P—ABC\)的体积为\(V_{2}\),则\(\dfrac{{{V}_{1}}}{{{V}_{2}}}=\_\_\_\_\_\_\_\_\).

              \((4)\)已知函数\(f(x)\)是\(R\)上的奇函数,且对任意实数\(a\)、\(b\)当\(a+b\neq 0\)时,都有\(\dfrac{f(a)+f(b)}{a+b} > 0.\)如果存在实数\(x∈[1,3]\),使得不等式\(f(x-c)+f(x-c^{2}) > 0\)成立,则实数\(c\)的取值范围是________.

            • 7. 在平面直角坐标系\(xOy\)中,\(A\),\(B\)为\(x\)轴正半轴上的两个动点,\(P(\)异于原点\(O)\)为\(y\)轴上的\(-\)个定点,若以\(AB\)为直径的圆与圆\(x^{2}+(y-2)^{2}=1\)相外切\(.\)且\(∠APB\)的大小恒为定值,则线段\(OP\)的长为______.
            • 8. 垂直于直线\(y=x+1\)且与圆\(x^{2}+y^{2}=1\)相切于第一象限的直线方程是\((\)  \()\)
              A.\(x+y- \sqrt {2}=0\)
              B.\(x+y+1=0\)
              C.\(x+y-1=0\)
              D.\(x+y+ \sqrt {2}=0\)
            • 9.

              如果实数\(x\),\(y\)满足\({\left(x-2\right)}^{2}+{y}^{2}=3 \),那么\( \dfrac{y}{x} \)的最大值是\((\)    \()\)

              A.\( \dfrac{ \sqrt{3}}{3} \)
              B.\( \dfrac{ \sqrt{3}}{2} \)
              C.\( \sqrt{3} \)
              D.\( \dfrac{1}{2} \)
            • 10.

              已知圆\(C\):\({{\left( x-3 \right)}^{2}}+{{\left( y-4 \right)}^{2}}=4\),直线\(l\)过定点\(A\left( 1,0 \right)\).

              \((\)Ⅰ\()\)若\(l\)与圆\(C\)相切,求\(l\)的方程;

              \((\)Ⅱ\()\)若\(l\)与圆\(C\)相交于\(P\)、\(Q\)两点,求\(\Delta CPQ\)的面积的最大值,并求此时直线\(l\)的方程\(.(\)其中点\(C\)是圆\(C\)的圆心\()\)

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