1 . 设
,而
为S的一个8元子集.求证:
(1)存在非零自然数k,使得方程
至少有3组不同的解;
(2)对于S的7元子集
,(1)中的结论不再总是成立.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06018a972e02a43b95f5c78aca784610.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7bf032b085c415f6ce188bd9be0afe6.png)
(1)存在非零自然数k,使得方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aae335e59364467c2ad9d5602f220af2.png)
(2)对于S的7元子集
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7c1f4838725717094b55f5d82a3e2ca.png)
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名校
2 . 已知
均为正数,并且
,给出下列2个结论:
①
中小于1的数最多只有一个;
②
中最小的数不小于
.则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f1a2f40c3c0853c0d5a4150a9d3fc80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58d6194de86fc1fdaa85646c25cbc67a.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f1a2f40c3c0853c0d5a4150a9d3fc80.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f1a2f40c3c0853c0d5a4150a9d3fc80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca83504e351d7516f61a3052d7a31859.png)
A.①对,②错 | B.①错,②对 |
C.①,②都错 | D.①,②都对 |
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2023-12-05更新
|
247次组卷
|
2卷引用:上海市嘉定区第一中学2023-2024学年高三上学期期中考试数学试卷
名校
3 . 命题“
,若
,则
或
”用反证法证明时应假设为____ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73254f32b6da29ecc32df2e9f87a4c97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f71a7888032847705f122e3ed0743ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a3c442579603164f3fc19458677d307.png)
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4 . 用反证法证明命题“
或
”时要做的假设是______________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fde64f4d3c38e43fbdee24eadc4b0dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eec336faee8689281a6f6b465e7fcff9.png)
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5 . 如果
同时满足以下三个条件:
①
;②对任意
,
成立;③当
,
,
时,总有
成立,则称
为“理想函数”.有下列两个命题:
命题
:若
为“理想函数”,则存在
且
,使
成立;
命题
:若
为“理想函数”,则对任意
,都有
成立.
则下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bf2489be061d0834df02c319a798e33.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/249a976e88133f3b3733f09137cf5c42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f7dbb416ec1ff1984a724a4f48bf692.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e9c599e8d420006448905acec2b8234.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12aae852c3129efc16934aefc54201f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24cd2fe62ffe3caa1c6f7976851c9dc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea2f51cd760aeff9365b51e9a85b41e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9f6988640a0b9bc4f9637132e6ca470.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
命题
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83a6c0fddb9074dfc96be03b4aa24d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26d8dafc71b106f39f4e15442220897b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ca3ecbbaca8eeb1cfa8f4035f7d5726.png)
命题
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f7dbb416ec1ff1984a724a4f48bf692.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d3c756a52c9185ae6d02d9b9312f29.png)
则下列说法正确的是( )
A.命题![]() ![]() | B.命题![]() ![]() |
C.命题![]() ![]() | D.命题![]() ![]() |
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2023-11-13更新
|
303次组卷
|
3卷引用:上海市建平中学2023-2024学年高一上学期期中数学试题
解题方法
6 . (1)设
为实数,比较
与
的值的大小;
(2)设
.用反证法证明:若
是奇数,则
是奇数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc997a4317a3b64369178b27abc44b95.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5e738d349de57804c74596f26f8f200.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b00438433719b82971f9fe309e04b5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411a315870ed3e6d0e8ea885f1a04bcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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名校
解题方法
7 . (1)已知实数
,
满足
,求证:
.
(2)若实数
,
为正数,且满足
,用反证法证明:
和
中至少有一个成立.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/432d77fe5ad3032d59a237dd94c8a638.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/838b9f49811c77cbf7d12d3af4a63373.png)
(2)若实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a7dbc702617c765a573961953cc0901.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eba1d7973f41f2050afd1759a0e480e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dfd31530f4f4d297248c3e39f42d8fb.png)
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解题方法
8 . (1)设
,
用反证法证明:若
,则
或
.
(2)设
,比较
与
的值的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f370a1d4dd341e5ab1774a66c66c1204.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ae3aa00a59d5e1db4efb0aa7ece4623.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fde64f4d3c38e43fbdee24eadc4b0dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eec336faee8689281a6f6b465e7fcff9.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10bbdef421c976962a270a2beabbad91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc997a4317a3b64369178b27abc44b95.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f814b4dc5876d8bf3aa145593bf4cc66.png)
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2023-11-09更新
|
74次组卷
|
2卷引用:上海市奉贤区四校联考2023-2024学年高一上学期期中数学试题
名校
解题方法
9 . (1)用反证法证明:对任意的
,关于
的方程
与
至少有一个方程有实根;
(2)若不等式
对于一切实数
都成立,求实数
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2725a89d93c791f7a0098f4964587905.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8488e2f76390a40e4f14de417c2a4b46.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4948941e66091d25a45fbea40c44ea85.png)
(2)若不等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b56faaf0c9eee7ee0cebbd3416dbc9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
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10 . 用反证法证明:“若
,则
或
”时,应假设____________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3898b62d3fbcb61afb6bc1e9b910f564.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef00713e73b8357cc7900144f5505bc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f23d29646155e27b172ecdf263e2d702.png)
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