返回特征解读

2019 年全国高中数学联赛 A 卷(学生版)

books/national_high_school_league_students/papers/competition-national-league-2019-a.pdf · HS-MATH-1024-v2.1-solution-aware

150 个小问/题组
1

一试(A 卷) · 一、填空题:本大题共 8 小题,每小题 8 分,满分 64 分. · 数学竞赛/待细分

已知正实数 a\htmlData{tutor-start=0,tutor-end=1}{a} 满足 aa=(9a)8a\htmlData{tutor-start=0,tutor-end=1}{a}^{\htmlData{tutor-start=3,tutor-end=4}{a}}\htmlData{tutor-start=5,tutor-end=6}{=}\htmlData{tutor-start=6,tutor-end=7}{(}\htmlData{tutor-start=7,tutor-end=8}{9}\htmlData{tutor-start=8,tutor-end=9}{a}\htmlData{tutor-start=9,tutor-end=10}{)}^{\htmlData{tutor-start=12,tutor-end=13}{8}\htmlData{tutor-start=13,tutor-end=14}{a}},则 loga(3a)\log_{\htmlData{tutor-start=6,tutor-end=7}{a}}\htmlData{tutor-start=8,tutor-end=9}{(}\htmlData{tutor-start=9,tutor-end=10}{3}\htmlData{tutor-start=10,tutor-end=11}{a}\htmlData{tutor-start=11,tutor-end=12}{)} 的值为__________.

题解状态:标准答案与规范题解待补充

题目标签:FIRST-A-FILL-P1

解题过程

该题已完成题面、原题号、PDF 来源锚定和题目级特征标注;答案、证明步骤与教材关联尚未录入。

2

一试(A 卷) · 一、填空题:本大题共 8 小题,每小题 8 分,满分 64 分. · 组合数学

若实数集合 {1,2,3,x}\htmlData{tutor-start=0,tutor-end=2}{\{}\htmlData{tutor-start=2,tutor-end=3}{1}\htmlData{tutor-start=3,tutor-end=4}{,}\htmlData{tutor-start=4,tutor-end=5}{2}\htmlData{tutor-start=5,tutor-end=6}{,}\htmlData{tutor-start=6,tutor-end=7}{3}\htmlData{tutor-start=7,tutor-end=8}{,}\htmlData{tutor-start=8,tutor-end=9}{x}\htmlData{tutor-start=9,tutor-end=11}{\}} 的最大元素与最小元素之差等于该集合的所有元素之和,则 x\htmlData{tutor-start=0,tutor-end=1}{x} 的值为__________.

题解状态:标准答案与规范题解待补充

题目标签:FIRST-A-FILL-P2

解题过程

该题已完成题面、原题号、PDF 来源锚定和题目级特征标注;答案、证明步骤与教材关联尚未录入。

3

一试(A 卷) · 一、填空题:本大题共 8 小题,每小题 8 分,满分 64 分. · 数学竞赛/待细分

平面直角坐标系中,e\vec{\htmlData{tutor-start=5,tutor-end=6}{e}} 是单位向量,向量 a\vec{\htmlData{tutor-start=5,tutor-end=6}{a}} 满足 ae=2\vec{\htmlData{tutor-start=5,tutor-end=6}{a}} \htmlData{tutor-start=8,tutor-end=14}{\cdot }\vec{\htmlData{tutor-start=19,tutor-end=20}{e}}\htmlData{tutor-start=21,tutor-end=22}{=}\htmlData{tutor-start=22,tutor-end=23}{2},且 a25a+te\htmlData{tutor-start=0,tutor-end=1}{|}\vec{\htmlData{tutor-start=6,tutor-end=7}{a}}\htmlData{tutor-start=8,tutor-end=9}{|}^{\htmlData{tutor-start=11,tutor-end=12}{2}} \htmlData{tutor-start=14,tutor-end=18}{\le }\htmlData{tutor-start=18,tutor-end=19}{5}\htmlData{tutor-start=19,tutor-end=20}{|}\vec{\htmlData{tutor-start=25,tutor-end=26}{a}}\htmlData{tutor-start=27,tutor-end=28}{+}\htmlData{tutor-start=28,tutor-end=29}{t}\vec{\htmlData{tutor-start=34,tutor-end=35}{e}}\htmlData{tutor-start=36,tutor-end=37}{|} 对任意实数 t\htmlData{tutor-start=0,tutor-end=1}{t} 成立,则 a\htmlData{tutor-start=0,tutor-end=1}{|}\vec{\htmlData{tutor-start=6,tutor-end=7}{a}}\htmlData{tutor-start=8,tutor-end=9}{|} 的取值范围是__________.

题解状态:标准答案与规范题解待补充

题目标签:FIRST-A-FILL-P3

解题过程

该题已完成题面、原题号、PDF 来源锚定和题目级特征标注;答案、证明步骤与教材关联尚未录入。

4

一试(A 卷) · 一、填空题:本大题共 8 小题,每小题 8 分,满分 64 分. · 平面几何

设 A,B 为椭圆 Γ\htmlData{tutor-start=0,tutor-end=6}{\Gamma} 的长轴顶点,E,F 为 Γ\htmlData{tutor-start=0,tutor-end=6}{\Gamma} 的两个焦点,AB=4,AF=2+3\htmlData{tutor-start=0,tutor-end=1}{|}\htmlData{tutor-start=1,tutor-end=2}{A}\htmlData{tutor-start=2,tutor-end=3}{B}\htmlData{tutor-start=3,tutor-end=4}{|}\htmlData{tutor-start=4,tutor-end=5}{=}\htmlData{tutor-start=5,tutor-end=6}{4}\htmlData{tutor-start=6,tutor-end=7}{,} \htmlData{tutor-start=8,tutor-end=9}{|}\htmlData{tutor-start=9,tutor-end=10}{A}\htmlData{tutor-start=10,tutor-end=11}{F}\htmlData{tutor-start=11,tutor-end=12}{|}\htmlData{tutor-start=12,tutor-end=13}{=}\htmlData{tutor-start=13,tutor-end=14}{2}\htmlData{tutor-start=14,tutor-end=15}{+}\sqrt{\htmlData{tutor-start=21,tutor-end=22}{3}},P 为 Γ\htmlData{tutor-start=0,tutor-end=6}{\Gamma} 上一点,满足 PEPF=2\htmlData{tutor-start=0,tutor-end=1}{|}\htmlData{tutor-start=1,tutor-end=2}{P}\htmlData{tutor-start=2,tutor-end=3}{E}\htmlData{tutor-start=3,tutor-end=4}{|} \htmlData{tutor-start=5,tutor-end=11}{\cdot }\htmlData{tutor-start=11,tutor-end=12}{|}\htmlData{tutor-start=12,tutor-end=13}{P}\htmlData{tutor-start=13,tutor-end=14}{F}\htmlData{tutor-start=14,tutor-end=15}{|}\htmlData{tutor-start=15,tutor-end=16}{=}\htmlData{tutor-start=16,tutor-end=17}{2},则 ΔPEF\htmlData{tutor-start=0,tutor-end=7}{\Delta }\htmlData{tutor-start=7,tutor-end=8}{P}\htmlData{tutor-start=8,tutor-end=9}{E}\htmlData{tutor-start=9,tutor-end=10}{F} 的面积为__________.

题解状态:标准答案与规范题解待补充

题目标签:FIRST-A-FILL-P4

解题过程

该题已完成题面、原题号、PDF 来源锚定和题目级特征标注;答案、证明步骤与教材关联尚未录入。

5

一试(A 卷) · 一、填空题:本大题共 8 小题,每小题 8 分,满分 64 分. · 数论

1,2,3,,10\htmlData{tutor-start=0,tutor-end=1}{1}\htmlData{tutor-start=1,tutor-end=2}{,}\htmlData{tutor-start=2,tutor-end=3}{2}\htmlData{tutor-start=3,tutor-end=4}{,}\htmlData{tutor-start=4,tutor-end=5}{3}\htmlData{tutor-start=5,tutor-end=6}{,} \cdots\htmlData{tutor-start=13,tutor-end=14}{,} \htmlData{tutor-start=15,tutor-end=16}{1}\htmlData{tutor-start=16,tutor-end=17}{0} 中随机选出一个数 a\htmlData{tutor-start=0,tutor-end=1}{a},在 1,2,3,,10\htmlData{tutor-start=0,tutor-end=1}{-}\htmlData{tutor-start=1,tutor-end=2}{1}\htmlData{tutor-start=2,tutor-end=3}{,}\htmlData{tutor-start=3,tutor-end=4}{-}\htmlData{tutor-start=4,tutor-end=5}{2}\htmlData{tutor-start=5,tutor-end=6}{,}\htmlData{tutor-start=6,tutor-end=7}{-}\htmlData{tutor-start=7,tutor-end=8}{3}\htmlData{tutor-start=8,tutor-end=9}{,} \cdots\htmlData{tutor-start=16,tutor-end=17}{,} \htmlData{tutor-start=18,tutor-end=19}{-}\htmlData{tutor-start=19,tutor-end=20}{1}\htmlData{tutor-start=20,tutor-end=21}{0} 中随机选出一个数 b\htmlData{tutor-start=0,tutor-end=1}{b},则 a2+b\htmlData{tutor-start=0,tutor-end=1}{a}^{\htmlData{tutor-start=3,tutor-end=4}{2}}\htmlData{tutor-start=5,tutor-end=6}{+}\htmlData{tutor-start=6,tutor-end=7}{b} 被 3 整除的概率为__________.

题解状态:标准答案与规范题解待补充

题目标签:FIRST-A-FILL-P5

解题过程

该题已完成题面、原题号、PDF 来源锚定和题目级特征标注;答案、证明步骤与教材关联尚未录入。

6

一试(A 卷) · 一、填空题:本大题共 8 小题,每小题 8 分,满分 64 分. · 代数

对任意闭区间 I\htmlData{tutor-start=0,tutor-end=1}{I},用 MI\htmlData{tutor-start=0,tutor-end=1}{M}_{\htmlData{tutor-start=3,tutor-end=4}{I}} 表示函数 y=sinx\htmlData{tutor-start=0,tutor-end=1}{y}\htmlData{tutor-start=1,tutor-end=2}{=}\sin \htmlData{tutor-start=7,tutor-end=8}{x}I\htmlData{tutor-start=0,tutor-end=1}{I} 上的最大值. 若正数 a\htmlData{tutor-start=0,tutor-end=1}{a} 满足 M[0,a]=2M[a,2a]\htmlData{tutor-start=0,tutor-end=1}{M}_{\htmlData{tutor-start=3,tutor-end=4}{[}\htmlData{tutor-start=4,tutor-end=5}{0}\htmlData{tutor-start=5,tutor-end=6}{,}\htmlData{tutor-start=6,tutor-end=7}{a}\htmlData{tutor-start=7,tutor-end=8}{]}}\htmlData{tutor-start=9,tutor-end=10}{=}\htmlData{tutor-start=10,tutor-end=11}{2}\htmlData{tutor-start=11,tutor-end=12}{M}_{\htmlData{tutor-start=14,tutor-end=15}{[}\htmlData{tutor-start=15,tutor-end=16}{a}\htmlData{tutor-start=16,tutor-end=17}{,}\htmlData{tutor-start=17,tutor-end=18}{2}\htmlData{tutor-start=18,tutor-end=19}{a}\htmlData{tutor-start=19,tutor-end=20}{]}},则 a\htmlData{tutor-start=0,tutor-end=1}{a} 的值为__________.

题解状态:标准答案与规范题解待补充

题目标签:FIRST-A-FILL-P6

解题过程

该题已完成题面、原题号、PDF 来源锚定和题目级特征标注;答案、证明步骤与教材关联尚未录入。

7

一试(A 卷) · 一、填空题:本大题共 8 小题,每小题 8 分,满分 64 分. · 组合数学

如图,正方体 ABCD — EFGH 的一个截面经过顶点 A,C 及棱 EF 上一点 K,且将正方体分成体积比为 3:1 的两部分,则 EKKF\frac{\htmlData{tutor-start=6,tutor-end=7}{E}\htmlData{tutor-start=7,tutor-end=8}{K}}{\htmlData{tutor-start=10,tutor-end=11}{K}\htmlData{tutor-start=11,tutor-end=12}{F}} 的值为__________.

原卷图示 1
原卷图示 1原卷第 1 页 · qwen3.7-plus_layout_detection · 需复核

题解状态:标准答案与规范题解待补充

题目标签:FIRST-A-FILL-P7

解题过程

该题已完成题面、原题号、PDF 来源锚定和题目级特征标注;答案、证明步骤与教材关联尚未录入。

8

一试(A 卷) · 一、填空题:本大题共 8 小题,每小题 8 分,满分 64 分. · 数学竞赛/待细分

将 6 个数 2,0,1,9,20,19 按任意次序排成一行,拼成一个 8 位数(首位不为 0),则产生的不同的 8 位数的个数为__________.

题解状态:标准答案与规范题解待补充

题目标签:FIRST-A-FILL-P8

解题过程

该题已完成题面、原题号、PDF 来源锚定和题目级特征标注;答案、证明步骤与教材关联尚未录入。

9

一试(A 卷) · 二、解答题:本大题共 3 小题,满分 56 分. 解答应写出文字说明、证明过程或演算步骤. · 平面几何

(本题满分 16 分)在 ABC\htmlData{tutor-start=0,tutor-end=10}{\triangle }\htmlData{tutor-start=10,tutor-end=11}{A}\htmlData{tutor-start=11,tutor-end=12}{B}\htmlData{tutor-start=12,tutor-end=13}{C} 中,BC=a\htmlData{tutor-start=0,tutor-end=1}{B}\htmlData{tutor-start=1,tutor-end=2}{C}\htmlData{tutor-start=2,tutor-end=3}{=}\htmlData{tutor-start=3,tutor-end=4}{a}CA=b\htmlData{tutor-start=0,tutor-end=1}{C}\htmlData{tutor-start=1,tutor-end=2}{A}\htmlData{tutor-start=2,tutor-end=3}{=}\htmlData{tutor-start=3,tutor-end=4}{b}AB=c\htmlData{tutor-start=0,tutor-end=1}{A}\htmlData{tutor-start=1,tutor-end=2}{B}\htmlData{tutor-start=2,tutor-end=3}{=}\htmlData{tutor-start=3,tutor-end=4}{c}.若 b\htmlData{tutor-start=0,tutor-end=1}{b}a\htmlData{tutor-start=0,tutor-end=1}{a}c\htmlData{tutor-start=0,tutor-end=1}{c} 的等比中项,且 sinA\sin \htmlData{tutor-start=5,tutor-end=6}{A}sin(BA)\sin\htmlData{tutor-start=4,tutor-end=5}{(}\htmlData{tutor-start=5,tutor-end=6}{B}\htmlData{tutor-start=6,tutor-end=7}{-}\htmlData{tutor-start=7,tutor-end=8}{A}\htmlData{tutor-start=8,tutor-end=9}{)}sinC\sin \htmlData{tutor-start=5,tutor-end=6}{C} 的等差中项,求 cosB\cos \htmlData{tutor-start=5,tutor-end=6}{B} 的值.

题解状态:标准答案与规范题解待补充

题目标签:FIRST-A-SOLUTION-P9

解题过程

该题已完成题面、原题号、PDF 来源锚定和题目级特征标注;答案、证明步骤与教材关联尚未录入。

10

一试(A 卷) · 二、解答题:本大题共 3 小题,满分 56 分. 解答应写出文字说明、证明过程或演算步骤. · 平面几何

(本题满分 20 分)在平面直角坐标系 xOy\htmlData{tutor-start=0,tutor-end=1}{x}\htmlData{tutor-start=1,tutor-end=2}{O}\htmlData{tutor-start=2,tutor-end=3}{y} 中,圆 W 与抛物线 G:y2=4x\htmlData{tutor-start=0,tutor-end=1}{y}^{\htmlData{tutor-start=3,tutor-end=4}{2}}\htmlData{tutor-start=5,tutor-end=6}{=}\htmlData{tutor-start=6,tutor-end=7}{4}\htmlData{tutor-start=7,tutor-end=8}{x} 恰有一个公共点,且圆 W 与 x\htmlData{tutor-start=0,tutor-end=1}{x} 轴相切于 G 的焦点 F\htmlData{tutor-start=0,tutor-end=1}{F}.求圆 W 的半径.

题解状态:标准答案与规范题解待补充

题目标签:FIRST-A-SOLUTION-P10

解题过程

该题已完成题面、原题号、PDF 来源锚定和题目级特征标注;答案、证明步骤与教材关联尚未录入。

11

一试(A 卷) · 二、解答题:本大题共 3 小题,满分 56 分. 解答应写出文字说明、证明过程或演算步骤. · 数论

(本题满分 20 分)称一个复数数列 {zn}\htmlData{tutor-start=0,tutor-end=2}{\{}\htmlData{tutor-start=2,tutor-end=3}{z}_{\htmlData{tutor-start=5,tutor-end=6}{n}}\htmlData{tutor-start=7,tutor-end=9}{\}} 为“有趣的”,若 z1=1\htmlData{tutor-start=0,tutor-end=1}{|}\htmlData{tutor-start=1,tutor-end=2}{z}_{\htmlData{tutor-start=4,tutor-end=5}{1}}\htmlData{tutor-start=6,tutor-end=7}{|}\htmlData{tutor-start=7,tutor-end=8}{=}\htmlData{tutor-start=8,tutor-end=9}{1},且对任意正整数 n,均有 4zn+12+2znzn+1+zn2=0\htmlData{tutor-start=0,tutor-end=1}{4}\htmlData{tutor-start=1,tutor-end=2}{z}_{\htmlData{tutor-start=4,tutor-end=5}{n}\htmlData{tutor-start=5,tutor-end=6}{+}\htmlData{tutor-start=6,tutor-end=7}{1}}^{\htmlData{tutor-start=10,tutor-end=11}{2}}\htmlData{tutor-start=12,tutor-end=13}{+}\htmlData{tutor-start=13,tutor-end=14}{2}\htmlData{tutor-start=14,tutor-end=15}{z}_{\htmlData{tutor-start=17,tutor-end=18}{n}} \htmlData{tutor-start=20,tutor-end=21}{z}_{\htmlData{tutor-start=23,tutor-end=24}{n}\htmlData{tutor-start=24,tutor-end=25}{+}\htmlData{tutor-start=25,tutor-end=26}{1}}\htmlData{tutor-start=27,tutor-end=28}{+}\htmlData{tutor-start=28,tutor-end=29}{z}_{\htmlData{tutor-start=31,tutor-end=32}{n}}^{\htmlData{tutor-start=35,tutor-end=36}{2}}\htmlData{tutor-start=37,tutor-end=38}{=}\htmlData{tutor-start=38,tutor-end=39}{0}.求最大的常数 C,使得对一切有趣的数列 {zn}\htmlData{tutor-start=0,tutor-end=2}{\{}\htmlData{tutor-start=2,tutor-end=3}{z}_{\htmlData{tutor-start=5,tutor-end=6}{n}}\htmlData{tutor-start=7,tutor-end=9}{\}} 及任意正整数 m,均有 z1+z2+zmC\htmlData{tutor-start=0,tutor-end=1}{|}\htmlData{tutor-start=1,tutor-end=2}{z}_{\htmlData{tutor-start=4,tutor-end=5}{1}}\htmlData{tutor-start=6,tutor-end=7}{+}\htmlData{tutor-start=7,tutor-end=8}{z}_{\htmlData{tutor-start=10,tutor-end=11}{2}}\htmlData{tutor-start=12,tutor-end=13}{+}\cdots \htmlData{tutor-start=20,tutor-end=21}{z}_{\htmlData{tutor-start=23,tutor-end=24}{m}}\htmlData{tutor-start=25,tutor-end=26}{|}\htmlData{tutor-start=26,tutor-end=30}{\ge }\htmlData{tutor-start=30,tutor-end=31}{C}

题解状态:标准答案与规范题解待补充

题目标签:FIRST-A-SOLUTION-P11

解题过程

该题已完成题面、原题号、PDF 来源锚定和题目级特征标注;答案、证明步骤与教材关联尚未录入。

12

二试/加试(A 卷) · 一、(本题满分 40 分) · 平面几何

如图,在锐角 ABC\htmlData{tutor-start=0,tutor-end=10}{\triangle }\htmlData{tutor-start=10,tutor-end=11}{A}\htmlData{tutor-start=11,tutor-end=12}{B}\htmlData{tutor-start=12,tutor-end=13}{C} 中,M\htmlData{tutor-start=0,tutor-end=1}{M}BC\htmlData{tutor-start=0,tutor-end=1}{B}\htmlData{tutor-start=1,tutor-end=2}{C} 边的中点,点 P\htmlData{tutor-start=0,tutor-end=1}{P}ABC\htmlData{tutor-start=0,tutor-end=10}{\triangle }\htmlData{tutor-start=10,tutor-end=11}{A}\htmlData{tutor-start=11,tutor-end=12}{B}\htmlData{tutor-start=12,tutor-end=13}{C} 内,使得 AP\htmlData{tutor-start=0,tutor-end=1}{A}\htmlData{tutor-start=1,tutor-end=2}{P} 平分 BAC\htmlData{tutor-start=0,tutor-end=7}{\angle }\htmlData{tutor-start=7,tutor-end=8}{B}\htmlData{tutor-start=8,tutor-end=9}{A}\htmlData{tutor-start=9,tutor-end=10}{C}。直线 MP\htmlData{tutor-start=0,tutor-end=1}{M}\htmlData{tutor-start=1,tutor-end=2}{P}ABP,ACP\htmlData{tutor-start=0,tutor-end=10}{\triangle }\htmlData{tutor-start=10,tutor-end=11}{A}\htmlData{tutor-start=11,tutor-end=12}{B}\htmlData{tutor-start=12,tutor-end=13}{P}\htmlData{tutor-start=13,tutor-end=14}{,} \htmlData{tutor-start=15,tutor-end=25}{\triangle }\htmlData{tutor-start=25,tutor-end=26}{A}\htmlData{tutor-start=26,tutor-end=27}{C}\htmlData{tutor-start=27,tutor-end=28}{P} 的外接圆分别相交于不同于点 P\htmlData{tutor-start=0,tutor-end=1}{P} 的两点 D,E\htmlData{tutor-start=0,tutor-end=1}{D}\htmlData{tutor-start=1,tutor-end=2}{,} \htmlData{tutor-start=3,tutor-end=4}{E}。证明:若 DE=MP\htmlData{tutor-start=0,tutor-end=1}{D}\htmlData{tutor-start=1,tutor-end=2}{E}\htmlData{tutor-start=2,tutor-end=3}{=}\htmlData{tutor-start=3,tutor-end=4}{M}\htmlData{tutor-start=4,tutor-end=5}{P},则 BC=2BP\htmlData{tutor-start=0,tutor-end=1}{B}\htmlData{tutor-start=1,tutor-end=2}{C}\htmlData{tutor-start=2,tutor-end=3}{=}\htmlData{tutor-start=3,tutor-end=4}{2}\htmlData{tutor-start=4,tutor-end=5}{B}\htmlData{tutor-start=5,tutor-end=6}{P}

原卷图示 1
原卷图示 1原卷第 3 页 · qwen3.7-plus_layout_detection · 需复核

题解状态:标准答案与规范题解待补充

题目标签:SECOND-A-SOLUTION-P一

解题过程

该题已完成题面、原题号、PDF 来源锚定和题目级特征标注;答案、证明步骤与教材关联尚未录入。

13

二试/加试(A 卷) · 二、(本题满分 40 分) · 数论

设整数 a1,a2,,a2019\htmlData{tutor-start=0,tutor-end=1}{a}_{\htmlData{tutor-start=3,tutor-end=4}{1}}\htmlData{tutor-start=5,tutor-end=6}{,} \htmlData{tutor-start=7,tutor-end=8}{a}_{\htmlData{tutor-start=10,tutor-end=11}{2}}\htmlData{tutor-start=12,tutor-end=13}{,} \cdots\htmlData{tutor-start=20,tutor-end=21}{,} \htmlData{tutor-start=22,tutor-end=23}{a}_{\htmlData{tutor-start=25,tutor-end=26}{2}\htmlData{tutor-start=26,tutor-end=27}{0}\htmlData{tutor-start=27,tutor-end=28}{1}\htmlData{tutor-start=28,tutor-end=29}{9}} 满足 1=a1a2a2019=99\htmlData{tutor-start=0,tutor-end=1}{1}\htmlData{tutor-start=1,tutor-end=2}{=}\htmlData{tutor-start=2,tutor-end=3}{a}_{\htmlData{tutor-start=5,tutor-end=6}{1}} \htmlData{tutor-start=8,tutor-end=12}{\le }\htmlData{tutor-start=12,tutor-end=13}{a}_{\htmlData{tutor-start=15,tutor-end=16}{2}} \htmlData{tutor-start=18,tutor-end=22}{\le }\cdots \htmlData{tutor-start=29,tutor-end=33}{\le }\htmlData{tutor-start=33,tutor-end=34}{a}_{\htmlData{tutor-start=36,tutor-end=37}{2}\htmlData{tutor-start=37,tutor-end=38}{0}\htmlData{tutor-start=38,tutor-end=39}{1}\htmlData{tutor-start=39,tutor-end=40}{9}}\htmlData{tutor-start=41,tutor-end=42}{=}\htmlData{tutor-start=42,tutor-end=43}{9}\htmlData{tutor-start=43,tutor-end=44}{9}。记 f=(a12+a22++a20192)(a1a3+a2a4+a3a5++a2017a2019)\htmlData{tutor-start=0,tutor-end=1}{f}\htmlData{tutor-start=1,tutor-end=2}{=}\htmlData{tutor-start=2,tutor-end=3}{(}\htmlData{tutor-start=3,tutor-end=4}{a}_{\htmlData{tutor-start=6,tutor-end=7}{1}}^{\htmlData{tutor-start=10,tutor-end=11}{2}}\htmlData{tutor-start=12,tutor-end=13}{+}\htmlData{tutor-start=13,tutor-end=14}{a}_{\htmlData{tutor-start=16,tutor-end=17}{2}}^{\htmlData{tutor-start=20,tutor-end=21}{2}}\htmlData{tutor-start=22,tutor-end=23}{+}\cdots\htmlData{tutor-start=29,tutor-end=30}{+}\htmlData{tutor-start=30,tutor-end=31}{a}_{\htmlData{tutor-start=33,tutor-end=34}{2}\htmlData{tutor-start=34,tutor-end=35}{0}\htmlData{tutor-start=35,tutor-end=36}{1}\htmlData{tutor-start=36,tutor-end=37}{9}}^{\htmlData{tutor-start=40,tutor-end=41}{2}}\htmlData{tutor-start=42,tutor-end=43}{)}\htmlData{tutor-start=43,tutor-end=44}{-}\htmlData{tutor-start=44,tutor-end=45}{(}\htmlData{tutor-start=45,tutor-end=46}{a}_{\htmlData{tutor-start=48,tutor-end=49}{1}}\htmlData{tutor-start=50,tutor-end=51}{a}_{\htmlData{tutor-start=53,tutor-end=54}{3}}\htmlData{tutor-start=55,tutor-end=56}{+}\htmlData{tutor-start=56,tutor-end=57}{a}_{\htmlData{tutor-start=59,tutor-end=60}{2}}\htmlData{tutor-start=61,tutor-end=62}{a}_{\htmlData{tutor-start=64,tutor-end=65}{4}}\htmlData{tutor-start=66,tutor-end=67}{+}\htmlData{tutor-start=67,tutor-end=68}{a}_{\htmlData{tutor-start=70,tutor-end=71}{3}}\htmlData{tutor-start=72,tutor-end=73}{a}_{\htmlData{tutor-start=75,tutor-end=76}{5}}\htmlData{tutor-start=77,tutor-end=78}{+}\cdots\htmlData{tutor-start=84,tutor-end=85}{+}\htmlData{tutor-start=85,tutor-end=86}{a}_{\htmlData{tutor-start=88,tutor-end=89}{2}\htmlData{tutor-start=89,tutor-end=90}{0}\htmlData{tutor-start=90,tutor-end=91}{1}\htmlData{tutor-start=91,tutor-end=92}{7}}\htmlData{tutor-start=93,tutor-end=94}{a}_{\htmlData{tutor-start=96,tutor-end=97}{2}\htmlData{tutor-start=97,tutor-end=98}{0}\htmlData{tutor-start=98,tutor-end=99}{1}\htmlData{tutor-start=99,tutor-end=100}{9}}\htmlData{tutor-start=101,tutor-end=102}{)}。求 f\htmlData{tutor-start=0,tutor-end=1}{f} 的最小值 f0\htmlData{tutor-start=0,tutor-end=1}{f}_{\htmlData{tutor-start=3,tutor-end=4}{0}},并确定使 f=f0\htmlData{tutor-start=0,tutor-end=1}{f}\htmlData{tutor-start=1,tutor-end=2}{=}\htmlData{tutor-start=2,tutor-end=3}{f}_{\htmlData{tutor-start=5,tutor-end=6}{0}} 成立的数组 (a1,a2,,a2019)\htmlData{tutor-start=0,tutor-end=1}{(}\htmlData{tutor-start=1,tutor-end=2}{a}_{\htmlData{tutor-start=4,tutor-end=5}{1}}\htmlData{tutor-start=6,tutor-end=7}{,} \htmlData{tutor-start=8,tutor-end=9}{a}_{\htmlData{tutor-start=11,tutor-end=12}{2}}\htmlData{tutor-start=13,tutor-end=14}{,} \cdots\htmlData{tutor-start=21,tutor-end=22}{,} \htmlData{tutor-start=23,tutor-end=24}{a}_{\htmlData{tutor-start=26,tutor-end=27}{2}\htmlData{tutor-start=27,tutor-end=28}{0}\htmlData{tutor-start=28,tutor-end=29}{1}\htmlData{tutor-start=29,tutor-end=30}{9}}\htmlData{tutor-start=31,tutor-end=32}{)} 的个数。

题解状态:标准答案与规范题解待补充

题目标签:SECOND-A-SOLUTION-P二

解题过程

该题已完成题面、原题号、PDF 来源锚定和题目级特征标注;答案、证明步骤与教材关联尚未录入。

14

二试/加试(A 卷) · 二试 · 数论

(本题满分 50 分)设 m\htmlData{tutor-start=0,tutor-end=1}{m} 为整数,m2\htmlData{tutor-start=0,tutor-end=1}{|}\htmlData{tutor-start=1,tutor-end=2}{m}\htmlData{tutor-start=2,tutor-end=3}{|} \htmlData{tutor-start=4,tutor-end=8}{\ge }\htmlData{tutor-start=8,tutor-end=9}{2}.整数数列 a1,a2,\htmlData{tutor-start=0,tutor-end=1}{a}_{\htmlData{tutor-start=3,tutor-end=4}{1}}\htmlData{tutor-start=5,tutor-end=6}{,} \htmlData{tutor-start=7,tutor-end=8}{a}_{\htmlData{tutor-start=10,tutor-end=11}{2}}\htmlData{tutor-start=12,tutor-end=13}{,} \cdots 满足:a1,a2\htmlData{tutor-start=0,tutor-end=1}{a}_{\htmlData{tutor-start=3,tutor-end=4}{1}}\htmlData{tutor-start=5,tutor-end=6}{,} \htmlData{tutor-start=7,tutor-end=8}{a}_{\htmlData{tutor-start=10,tutor-end=11}{2}} 不全为零,且对任意正整数 n\htmlData{tutor-start=0,tutor-end=1}{n},均有 an+2=an+1man\htmlData{tutor-start=0,tutor-end=1}{a}_{\htmlData{tutor-start=3,tutor-end=4}{n}\htmlData{tutor-start=4,tutor-end=5}{+}\htmlData{tutor-start=5,tutor-end=6}{2}} \htmlData{tutor-start=8,tutor-end=9}{=} \htmlData{tutor-start=10,tutor-end=11}{a}_{\htmlData{tutor-start=13,tutor-end=14}{n}\htmlData{tutor-start=14,tutor-end=15}{+}\htmlData{tutor-start=15,tutor-end=16}{1}} \htmlData{tutor-start=18,tutor-end=19}{-} \htmlData{tutor-start=20,tutor-end=21}{m} \htmlData{tutor-start=22,tutor-end=23}{a}_{\htmlData{tutor-start=25,tutor-end=26}{n}}. 证明:若存在整数 r,s\htmlData{tutor-start=0,tutor-end=1}{r}\htmlData{tutor-start=1,tutor-end=2}{,} \htmlData{tutor-start=3,tutor-end=4}{s} (r>s2\htmlData{tutor-start=0,tutor-end=1}{r} \htmlData{tutor-start=2,tutor-end=3}{>} \htmlData{tutor-start=4,tutor-end=5}{s} \htmlData{tutor-start=6,tutor-end=10}{\ge }\htmlData{tutor-start=10,tutor-end=11}{2}) 使得 ar=as=a1\htmlData{tutor-start=0,tutor-end=1}{a}_{\htmlData{tutor-start=3,tutor-end=4}{r}} \htmlData{tutor-start=6,tutor-end=7}{=} \htmlData{tutor-start=8,tutor-end=9}{a}_{\htmlData{tutor-start=11,tutor-end=12}{s}} \htmlData{tutor-start=14,tutor-end=15}{=} \htmlData{tutor-start=16,tutor-end=17}{a}_{\htmlData{tutor-start=19,tutor-end=20}{1}},则 rsm\htmlData{tutor-start=0,tutor-end=1}{r} \htmlData{tutor-start=2,tutor-end=3}{-} \htmlData{tutor-start=4,tutor-end=5}{s} \htmlData{tutor-start=6,tutor-end=10}{\ge }\htmlData{tutor-start=10,tutor-end=11}{|}\htmlData{tutor-start=11,tutor-end=12}{m}\htmlData{tutor-start=12,tutor-end=13}{|}

题解状态:标准答案与规范题解待补充

题目标签:SECOND-A-PROBLEM-P三

解题过程

该题已完成题面、原题号、PDF 来源锚定和题目级特征标注;答案、证明步骤与教材关联尚未录入。

15

二试/加试(A 卷) · 二试 · 组合数学

(本题满分 50 分)设 V\htmlData{tutor-start=0,tutor-end=1}{V} 是空间中 2019 个点构成的集合,其中任意四点不共面.某些点之间连有线段,记 E\htmlData{tutor-start=0,tutor-end=1}{E} 为这些线段构成的集合.试求最小的正整数 n\htmlData{tutor-start=0,tutor-end=1}{n},满足条件:若 E\htmlData{tutor-start=0,tutor-end=1}{E} 至少有 n\htmlData{tutor-start=0,tutor-end=1}{n} 个元素,则 E\htmlData{tutor-start=0,tutor-end=1}{E} 一定含有 908 个二元子集,其中每个二元子集中的两条线段有公共端点,且任意两个二元子集的交为空集.

题解状态:标准答案与规范题解待补充

题目标签:SECOND-A-PROBLEM-P四

解题过程

该题已完成题面、原题号、PDF 来源锚定和题目级特征标注;答案、证明步骤与教材关联尚未录入。