1 . 对于问题“设实数
满足
,证明:
,
,
中至少有一个不超过
”.甲、乙、丙三个同学都用反证法来证明,他们的解题思路分别如下:
甲同学:假设对于满足
的任意实数
,
,
,
都大于
.
再找出一组满足
但与“
,
,
都大于
”矛盾的
,从而证明原命题.
乙同学:假设存在满足
的实数
,
,
,
都大于
.
再证明所有满足
的
均与“
,
,
都大于
”矛盾,从而证明原命题.
丙同学:假设存在满足
的实数
,
,
,
都大于
.
再证明所有满足
的
均与“
,
,
都大于
”矛盾,从而证明原命题.那么,下列正确的选项为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1f9223bc24df8d429d743692fff7c06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a13880b9454c5942f164d934b1834783.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/176400fc97133ee3a7bba932544318ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb00b6918dfb251c1a63acdc07464b92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5989c84e320b504511f23eeb6e7357.png)
甲同学:假设对于满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1f9223bc24df8d429d743692fff7c06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a13880b9454c5942f164d934b1834783.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/176400fc97133ee3a7bba932544318ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb00b6918dfb251c1a63acdc07464b92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5989c84e320b504511f23eeb6e7357.png)
再找出一组满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1f9223bc24df8d429d743692fff7c06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a13880b9454c5942f164d934b1834783.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/176400fc97133ee3a7bba932544318ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb00b6918dfb251c1a63acdc07464b92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5989c84e320b504511f23eeb6e7357.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
乙同学:假设存在满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1f9223bc24df8d429d743692fff7c06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a13880b9454c5942f164d934b1834783.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/176400fc97133ee3a7bba932544318ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb00b6918dfb251c1a63acdc07464b92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5989c84e320b504511f23eeb6e7357.png)
再证明所有满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1f9223bc24df8d429d743692fff7c06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a13880b9454c5942f164d934b1834783.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/176400fc97133ee3a7bba932544318ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb00b6918dfb251c1a63acdc07464b92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5989c84e320b504511f23eeb6e7357.png)
丙同学:假设存在满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9dad69e399b3b4f68b777f6678c7ced7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a13880b9454c5942f164d934b1834783.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/176400fc97133ee3a7bba932544318ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb00b6918dfb251c1a63acdc07464b92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5989c84e320b504511f23eeb6e7357.png)
再证明所有满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9dad69e399b3b4f68b777f6678c7ced7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a13880b9454c5942f164d934b1834783.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/176400fc97133ee3a7bba932544318ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb00b6918dfb251c1a63acdc07464b92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5989c84e320b504511f23eeb6e7357.png)
A.只有甲同学的解题思路正确 | B.只有乙同学的解题思路正确 |
C.只有丙同学的解题思路正确 | D.有两位同学的解题思路都正确 |
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2022-10-14更新
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111次组卷
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2卷引用:上海市浦东复旦附中分校2022-2023学年高一上学期10月月考数学试题