题型:填空题 题类:期中考试 难易度:中档
年份:2018
\((1)\)不等式\(\Delta ABD\)的解集为________.
\((2)\)若集合\(A=\left\{ x|a{{x}^{2}}-ax+1\leqslant 0 \right\}=\varnothing \),则实数\(a\)的取值范围是________.
\((3)\)设等比数列\(\left\{ {{a}_{n}} \right\}\)满足\(a_{1}+a_{3}=10\),\(a_{2}+a_{4}=5\),则\(a_{1}a_{2} …a_{n}\)的最大值为________.
\((4)\)如图,在\(Rt\Delta ABC\)中,\(\angle A={{90}^{0}}\),\(D,E\)分别是\(AC,BC\)上一点,满足\(\angle ADB=\angle CDE={{30}^{0}}\),\(BE=4CE.\)若\(CD=\sqrt{3}\),则\(\Delta BDE\)的面积为________.
题型:填空题 题类:期中考试 难易度:中档
年份:2018
\((1)\)函数\(f(x)=x(1-x)\),\(x∈(0,1)\)的最大值为__________.
\((2)\)在数列\(\{a_{n}\}\)中,其前\(n\)项和\(S_{n}=3·2^{n}+k\),若数列\(\{a_{n}\}\)是等比数列,则常数\(k\)的值为___________.
\((3)\)在\(∆ABC \)中\(A=60^{\circ} \),\(b=1\),面积为\(\sqrt{3} \),则\(\dfrac{a+b+c}{\sin A+\sin B+\sin C}= \)__________.
\((4)\)已知数列\(\{{a}_{n}\} \)满足\(2{a}_{1}+{2}^{2}{a}_{2}+{2}^{3}{a}_{3}+⋯+{2}^{n}{a}_{n}={4}^{n}-1 \),则\(\{{a}_{n}\} \)的通项公式_____________。
题型:填空题 题类:期中考试 难易度:难
年份:2018
\((1)\)函数\(f(x)=x(1-x)\),\(x∈(0,1)\)的最大值为__________.
\((2)\)在数列\(\{a_{n}\}\)中,其前\(n\)项和\(Sn=3·2n+k\),若数列\(\{a_{n}\}\)是等比数列,则常数\(k\)的值为___________.
\((3)\)在\(\triangle ABC\)中\(A=60^{\circ}\),\(b=1\),面积为\(\sqrt{3} \),则\(\dfrac{a+b+c}{\sin A+\sin B+\sin C}= \)__________.
\((4)\)已知数列\(\{an\}\)满足\(3{a}_{1}+{2}^{2}{a}_{2}+{2}^{3}{a}_{3}+⋯+{2}^{n}{a}_{n}={4}^{n}-1 \),则\(\{an\}\)的通项公式_____________。
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_____.