题型:填空题 题类:期中考试 难易度:较难
年份:2018
\((1)\)不等式\(\dfrac{x-1}{2x+1}\leqslant 0\)的解集为_____
\((2)\)已知数列\(\{a_{n}\}\)满足\({{a}_{1}}=\dfrac{1}{2},{{a}_{n+1}}=1-\dfrac{1}{{{a}_{n}}}\left( n\in {{N}_{+}} \right)\),则\({{a}_{16}}=\)_______
\((3)\triangle ABC\)中,已知\(a=x\),\(b=2\),\(B=60^{\circ}\),如果\(\triangle ABC\) 有两组解,则\(x\)的取值范围_____
\((4)\)已知等差数列\(\{a_{n}\}\)的首项\({{a}_{1}}=1\),公差\(d > 0\),且第\(2\)项,第\(5\)项,第\(14\)项分别是等比数列\(\{b_{n}\}\)的第\(2\)项,第\(3\)项,第\(4\)项。设数列\(\{c_{n}\}\)对 \(n∈N_{+}\)均有\({\,\!}\dfrac{{{c}_{1}}}{{{b}_{1}}}+\dfrac{{{c}_{2}}}{{{b}_{2}}}+...+\dfrac{{{c}_{n}}}{{{b}_{n}}}={{a}_{n+1}}\)成立,则数列\(\{c_{n}\}\)通项公式为_____
题型:填空题 题类:期中考试 难易度:较难
年份:2018
\((1)\)已知向量\(\overrightarrow{a}=\left(2,4\right) \),\(\overrightarrow{b}=\left(-1,m\right) \),且\(\overrightarrow{a} \)与\(\overrightarrow{a}-2 \overrightarrow{b} \)平行,则\(m\)等于_________.
\((2)\)设\(x\),\(y\)满足约束条件\(\begin{cases}1\leqslant x\leqslant 3 \\ -1\leqslant x-y\leqslant 0\end{cases} \),则\(z=2x-y \)的最大值为______.
\((3)\)设数列\(\left\{{a}_{n}\right\} \)是由正数组成的等比数列,\({S}_{n} \)为其前\(n\)项和,已知\({a}_{2}{a}_{4}=1,{S}_{3}=7 \),则\({S}_{5}= \)_______.
\((4)\)已知三棱锥\(P-ABC\)内接于球\(O\),\(PA=PB=PC=2\),当三棱锥\(P-ABC\)的三个侧面的面积之和最大时,球\(O\)的表面积为_____.
题型:填空题 题类:其他 难易度:较难
年份:2018
数列\(\left\{ {{a}_{n}} \right\}\)是公比为\(q\)的等比数列,其前\(n\)项和为\({{S}_{{n}}}\),且前\(n\)项积为\({{T}_{{n}}}\),且\(0{ < }a_{1}{ < }1{,}a_{2012}a_{2013}{=}1{,}\)则下列结论正确的是______ .
\(①{q} > 1\) \(②{{T}_{2013}} > 1\) \(③{{S}_{2012}}{{a}_{2013}} < {{S}_{2013}}{{a}_{2012}}\) \(④\)使\({{T}_{n}} > 1\)成立的最小自然数\(n\)为\(4025\) \(⑤{{\left( {{T}_{{n}}} \right)}_{\min }}={{T}_{2012}}\)
题型:填空题 题类:其他 难易度:较难
年份:2018