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            • 1.
              数列\(\{a_{n}\}\)满足\( \dfrac {1}{a_{n+1}}= \dfrac {1}{a_{n}}+1(n∈N_{+})\),数列\(\{b_{n}\}\)满足\(b_{n}= \dfrac {1}{a_{n}}\),且\(b_{1}+b_{2}+…+b_{9}=45\),则\(b_{4}b_{6}(\)  \()\)
              A.最大值为\(100\)
              B.最大值为\(25\)
              C.为定值\(24\)
              D.最大值为\(50\)
            • 2.

              \(F_{1}\),\(F_{2}\)是双曲线\(\dfrac{{{x}^{2}}}{4}-\dfrac{{{y}^{2}}}{45}=1\)的两个焦点,\(P\)是双曲线上的点,已知\(|PF_{1}|\),\(|PF_{2}|\),\(|F_{1}F_{2}|\)依次成等差数列,且公差大于\(0\),则\(∠F_{1}PF_{2}=\)______.

            • 3.

              设数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),若\(2\),\(S_{n}\),\(3a_{n}\)成等差数列,则\(S_{5}\)的值是\((\)    \()\)

              A.\(-243\)
              B.\(243\)
              C.\(-162\)
              D.\(-242\)
            • 4.

              \((1)\)若\(x\),\(y\)满足\(\begin{cases} & 2x-y\leqslant 0 \\ & x+y\leqslant \\ & x\geqslant 0 \\ \end{cases}\),则\(2x+y\)的最大值为________.

              \((2)\)若\(P=\dfrac{{{2017}^{2016}}+1}{{{2017}^{2017}}+1}\),\(Q=\dfrac{{{2017}^{2017}}+1}{{{2017}^{2018}}+1}\),则\(P\)和\(Q\)的大小关系为\(P\)________\(Q(\)用“\( > \)”、“\( < \)”或“\(=\)”填空\()\).

              \((3)\)等差数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),若\(a_{2}+a_{4}+a_{9}=24\),则\(\dfrac{{{S}_{8}}}{8}\cdot \dfrac{{{S}_{10}}}{10}\)的最大值为________.

              \((4)\)在等边三角形\(ABC\)中,\(P\)为三角形\(ABC\)内一动点,且\(∠BPC=120^{\circ}\),则\(\dfrac{PA}{PC}\)的最小值为________.

            • 5.

              填空题。

              \((1)\)求经过点\((-2,2)\),且与两坐标轴所围成的三角形面积为\(1\)的直线\(l\)的方程____________.

              \((2)《\)算法通宗\(》\)是我国古代内容丰富的数学名书,书中有如下问题:“远望巍巍塔七层,红灯向下倍加增,共灯三百八十一,请问塔顶几盏灯?”其意思为“一座塔共七层,从塔顶至塔底,每层灯的数目都是上一层的\(2\)倍,已知这座塔共有\(381\)盏灯,请问塔顶有几盏灯?”答____盏

              \((3)\)已知直线\(y=kx-k+1 \)恒过定点\(A\),若点\(A\)在直线\(mx+ny-1=0(mn > 0) \)上,则\( \dfrac{1}{m}+ \dfrac{1}{n} \)的最小值为        

              \((4)\)在\(\Delta ABC\)中,\(a,b,c \)是角\(A,B,C \)的对边,则下列结论正确的序号是_______

              \(①\) 若\(a,b,c \)成等差数列,则\({B}=\dfrac{\pi }{3}\);              

              \(②\) 若\(c=4,b=2 \sqrt{3},B= \dfrac{π}{6} \),则\(\Delta ABC\)有两解;

              \(③\) 若\(b=1,ac=2 \sqrt{3},B= \dfrac{π}{6} \),则\(a+c=2+\sqrt{3}\);    

              \(④\)若\((2c-b)\cos A=a\cos B\),则\(A=\dfrac{\pi }{6}\).

            • 6.

              \(( 1 )\)已知向量\( \overset{→}{a}, \overset{→}{b} \),满足\( \overset{→}{a}=(1,3) \),\(\left( \overset{→}{a}+ \overset{→}{b}\right)⊥\left( \overset{→}{a}- \overset{→}{b}\right) \),则\(\left| \overset{→}{b}\right| =\)______.

              \(( 2 )\)已知实数\(x\),\(y\)满足\(\begin{cases}x\leqslant 3 \\ x+y-3\geqslant 0 \\ x-y+1\geqslant 0\end{cases} \),则\({x}^{2}+{y}^{2}- \dfrac{1}{2} \)的最小值是     

              \(( 3 )\)若\(\left(x+3\right)(1- \dfrac{2}{ \sqrt{x}}{)}^{n} \)的展开式中常数项为\(43\),则\(∫_{2}^{n}2xdx= \)__________.

              \(( 4 )\)已知数列\(\left\{{a}_{n}\right\},\left\{{b}_{n}\right\} \)满足\({b}_{n}={\log }_{2}{a}_{n},n∈{N}^{*} \),其中\(\left\{{b}_{n}\right\} \)是等差数列,且\({a}_{9}{a}_{2009}=4 .\)则\({b}_{1}+{b}_{2}+{b}_{3}+⋯+{b}_{2017}= \)__________.

            • 7.

              已知数列\(\left\{ {{a}_{n}} \right\}\)是等差数列,\(A\)、\(B\)、\(C\)、\(D\)四点共面\((\)任意三点不共线\()\),\(O\)是空间中任意一点,且满足\(\overrightarrow{OA}={{a}_{5}}\overrightarrow{OB}+{{a}_{7}}\overrightarrow{OC}+{{a}_{9}}\overrightarrow{OD}\),则数列\(\left\{ {{a}_{n}} \right\}\)的前\(13\)项和为\((\) \()\)

              A.\(13\)   
              B.\(\dfrac{13}{3}\)
              C.\(\dfrac{13}{2}\)
              D.\(\dfrac{13}{4}\)
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