名校
1 . 课上我们学习了“
”符号和数学上陈述句
一些常用的否定形式
,实际上“若
,则
”为假命题可以表述为“至少存在特例
满足性质
,使
”,即我们常说的举反例.
(1)请利用上述逻辑语言说明以下两个命题为假:
①任何集合都不是空集的子集;②若
,则
;
(2)其他教材中有这样一种新命题的表述: 如果把命题“若
,则
”称为原命题,那么将其结论的否定作为条件,将其条件的否定作为结论,可以得到一个新命题“若
,则
”,我们称新命题为原命题的逆否命题.并且有一个非常强有力的结论:原命题与它的逆否命题是同真或同假的.请综合利用上述知识证明:对于正实数
,若
,则
;
(3)证明:原命题“若
,则
”与它的逆否命题“若
,则
”同为真命题或同为假命题.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ef73aff3fe470e367f4af24fdfff3df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d1c79d9d4f43ffb42f22c287058b5f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2303430b989c36a0c5380d64b3182690.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f2c566d4285f887b69c855f31849542.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e31113e042661f75628af5e3b2dc56f1.png)
(1)请利用上述逻辑语言说明以下两个命题为假:
①任何集合都不是空集的子集;②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52ddfcb6c5c9f8b50444386d7221154c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9138d5904f6ff2a48f29e820ce54e0e0.png)
(2)其他教材中有这样一种新命题的表述: 如果把命题“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/130adfc0b77a1bb4046c19fc52d5fe78.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73d277dac920ea0456d486ea528332f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632244ea6931507f8656e1cc3437d392.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/127a0d8c1c7d15ed40ec4b8bca0ebdf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/485a2d99320384a0857b00ce9ab9e990.png)
(3)证明:原命题“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d1c79d9d4f43ffb42f22c287058b5f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73d277dac920ea0456d486ea528332f0.png)
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名校
2 . 关于x的方程
,给出下列四个命题,其中真命题的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1160588efe90b4c33978434210b58dcf.png)
A.存在实数![]() |
B.存在实数![]() |
C.存在实数![]() |
D.存在实数![]() |
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2020-12-21更新
|
903次组卷
|
4卷引用:福建省仙游县第一中学2020-2021学年高一12月月考数学试题
福建省仙游县第一中学2020-2021学年高一12月月考数学试题(已下线)2.1 命题、定理、定义(课堂培优)-2021-2022学年高一数学课后培优练(苏教版2019必修第一册)山西省晋城市第一中学校2022-2023学年高一上学期第五次调研数学试题江苏省苏州市工业园区星海实验高级中学2023-2024学年高一上学期期末复习数学练习
名校
3 . 已知函数
,下列命题中:
①
在其定义域内有且仅有1个零点;
②
在其定义域内有且仅有1个极值点;
③
,使得
;
④
,
,使得
;
⑤当
时,函数
的图像总在函数
的图像的下方.
其中真命题有___________ .(写出所有真命题的序号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba28a28fd567c9331305ec91d04cf1ae.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42c10f7cdfb1c47057e702ae15a60cd8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/859458471c86ae39e0cc42d2d960d03e.png)
④
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/372e0890a16df97fc45675285f176033.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbf0c4df086f249d856fe6875ad6d890.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e2f24b4fa5308650a244d954f78f09b.png)
⑤当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fde64f4d3c38e43fbdee24eadc4b0dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d7adde0246fc0c3bfc8365d2bd04f21.png)
其中真命题有
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4 . 下列四个命题:①
,②
,③
,④
,其中真命题为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4e0591af6564320bcc7afc20faf25cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02d385ff6992b97090bffeb23e7a5ce5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d4352cd9d5a4717718429d0811e3078.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0fb683384aa8bae477a05a715a2e8a3.png)
A.①②③ | B.①③ | C.①②④ | D.③④ |
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解题方法
5 . 关于下列两个命题:设
是定义在
上的偶函数,且当
时,
单调,则方程
的所有根之和为______ ;对于
有性质
:“对
时,必有
.现给定①
;②
;现与
对比,①中
、②中
同样也有性质
的序号为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8b6894e8c345a035e89ec672503a01f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08115d6d9f876dea921a4d32260ff1fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8b6894e8c345a035e89ec672503a01f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50ab9a7e0459170b74091235ed37155c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b49e0a5e0946955251b7a2f3bfc21ed0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22d206c6853cb138f3d8db4f9acc9b99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b03422c87acca23dcc4e51e40221e2a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04cf321d8cf6a9c7adff9900857732b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6667b1e60410178985f7ee42e161abab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
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6 . 对于实数a,b,m,下列说法:①若
,则
;②若
,则
;③若
,则
;④若
,且
,则
的最小值为
.其中是真命题的为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/432d77fe5ad3032d59a237dd94c8a638.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef019ee5c3eff526b479ba9482e8a16b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/432d77fe5ad3032d59a237dd94c8a638.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cdea94e587e9a385a3df0ea3d2d71d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e86ddfc79ab750a8d2548e3a9e2b808b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58900a2822b9ff972d90440fced21584.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a0c4c098615c6bc7e6dcf72e5b5201a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1694f767d95499ef86d377afdc8bf08d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b0113fd4c7d157757571f9a009e02af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95bacae35b6e16a0a33c2bdc6bc07df7.png)
A.①② | B.②③ | C.③④ | D.①④ |
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2020-07-10更新
|
1719次组卷
|
4卷引用:2020年普通高等学校招生全国统一考试 文科数学样卷(八)
2020年普通高等学校招生全国统一考试 文科数学样卷(八)(已下线)第02练 常用逻辑用语-2021年高考数学(理)一轮复习小题必刷(已下线)第02练 常用逻辑用语-2021年高考数学(文)一轮复习小题必刷江西科技学院附属中学2021-2022学年高二上学期期中考试数学(理)试题
7 . 已知集合
.由集合P中所有的点组成的图形如图中阴影部分所示,中间白色部分形如美丽的“水滴”.给出下列结论:
①“水滴”图形与y轴相交,最高点记为A,则点A的坐标为
;
②在集合P中任取一点M,则M到原点的距离的最大值为3;
③阴影部分与y轴相交,最高点和最低点分别记为C,D,则
;
④白色“水滴”图形的面积是
.
其中正确的有______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1acb5ecf750be19dca1629d1be63754.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/30/9eef0590-d37a-4411-9fb5-96bfcb307fc9.png?resizew=184)
①“水滴”图形与y轴相交,最高点记为A,则点A的坐标为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a4fd84394e897ebf6c4814b841d427b.png)
②在集合P中任取一点M,则M到原点的距离的最大值为3;
③阴影部分与y轴相交,最高点和最低点分别记为C,D,则
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00a73f95b92dee46d63c5f0dc4316506.png)
④白色“水滴”图形的面积是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73e9521a4bda58b6a4cedac2d54fdca9.png)
其中正确的有
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2020-06-23更新
|
1269次组卷
|
3卷引用:北京市丰台区2020届高三下学期综合练习(二)(二模)数学试题
名校
8 . 给出以下四个命题:
①若
,则
;
②已知直线
与函数
,
的图像分别交于点
,则
的最大值为
;
③若数列
为单调递增数列,则
取值范围是
;
④已知数列
的通项
,前
项和为
,则使
的
的最小值为12.
其中正确命题的序号为__________ .
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3d6063ee5703cb140dfc69c9cde0bdb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8bfa5bb8b7d70c8dbf01bbc01d2b2019.png)
②已知直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36d71f015144ffaf1faec94a259b4a06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b923078510697d5f7f9ea392eb76dd9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8feb6516836167daab0bad41689b5d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac35b1e8a952aac4f4cdaaf02d868d04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
③若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7c33b314a69d8a715bfd7e1481f0463.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bcb74292380b8df9519b9c33bfd564f8.png)
④已知数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67c4593f37ce523cfa8fb5c102240319.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49763402b2f2023f0ba64c37924267d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
其中正确命题的序号为
您最近一年使用:0次
2020-05-22更新
|
779次组卷
|
3卷引用:广西南宁市第三中学2019-2020学年高一期中段考数学试题
解题方法
9 . 已知函数
(
且a为常数)和
(
且k为常数),有以下命题:①当
时,函数
没有零点;②当
时,若
恰有3个不同的零点
,则
;③对任意的
,总存在实数
,使得
有4个不同的零点
,且
成等比数列.其中的真命题是_____ (写出所有真命题的序号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/997aca47e77b0aa0230f881d4a37a1a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1e69392d21261afd8e5e5f096634669.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19d3d7b48ea2c4a0c74ebfb263c4eeb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37b97b295f88972ba1c7e3cefda0885d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44a4eaa80b44625890339d6a0065c241.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f3c2be7482719651bcf491949681e05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e541ea2f855f981c96207070683d388.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb4d3d9cd45cd44d30ca8390304a1652.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05b8ec9d4206ea66a02de5c4a1e1e911.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ceee16e55109607bdab345184fe61707.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f0d68648b10fce54dfc19c5ee60086d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4633de9335d15d7685bdecb007a3678c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3604274ad6707a906eba371a9e884144.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2094fde8741509f5614e2b66b77a7484.png)
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