1 . 命题“若
,则
”的否命题为__________ (填真或假)命题.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b384412acba251d87902ab928902f16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bad6987e8abfbf07d6a2650483d2a55.png)
您最近一年使用:0次
名校
2 . 命题“若
,则
”的否命题为__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4355caf38729df9b5a04ada9158620e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34c672fdac03ce0cc707e1d04fb0b753.png)
您最近一年使用:0次
2017-11-07更新
|
557次组卷
|
5卷引用:辽宁省葫芦岛市第六高级中学2017-2018学年高二上学期第二次阶段考试数学(理)试题
名校
3 . 下列命题中错误的是
A.命题“若x2﹣5x+6=0则x=2”的逆否命题是“若x≠2则x2﹣5x+6≠0” |
B.命题“已知x、y∈R,若x+y≠3,则x≠2或y≠1是真命题” |
C.已知命题p和q,若p∨q为真命题,则命题p与q中必一真一假 |
D.命题p:∃x0∈R,x02+x0+1<0,则¬p:∀x0∈R,x02+x0+1≥0 |
您最近一年使用:0次
2016-12-04更新
|
752次组卷
|
2卷引用:2015-2016学年辽宁省葫芦岛市高二上学期期末文科数学试卷
4 . 下列命题错误的是
A.命题“若![]() ![]() ![]() ![]() ![]() |
B.若![]() ![]() |
C.命题![]() ![]() ![]() ![]() ![]() ![]() ![]() |
D.“![]() ![]() |
您最近一年使用:0次
5 . 下列命题正确的个数是( )
①“在三角形
中,若
,则
”的否命题是真命题;
②命题
或
,命题
,则
是
的必要不充分条件;
③存在实数
,使
;
④命题“若
,则
有实根”的逆否命题是真命题.
①“在三角形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19dc38d888741a1b2e95fe0773a48c38.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca51be437b1a97ca92aa1159ab71102c.png)
②命题
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b4ad6bf033c2de624a30b57402f9142.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfe436ba908c76027255f3a677bf0657.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47bba0b621c9e99ce11132ddf3dec585.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
③存在实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79b752f0f189e5d8666daea73e145dff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d85685dd80e4f513558a36ccfbf21daf.png)
④命题“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e34f42b3be15518c29e3689c9fe6d6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d5707186257494f1fea86066f2778b5.png)
A.0 | B.1 | C.2 | D.3 |
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6 . 命题“若
,则
或
”的否命题为_____________________________ .
![](https://img.xkw.com/dksih/QBM/2016/1/20/1572448671006720/1572448677109760/STEM/e445d5d6e61c42c59d3fc86b9f2c18e8.png?resizew=68)
![](https://img.xkw.com/dksih/QBM/2016/1/20/1572448671006720/1572448677109760/STEM/63d54ec2a9c5438ca2fcc1820b178578.png?resizew=40)
![](https://img.xkw.com/dksih/QBM/2016/1/20/1572448671006720/1572448677109760/STEM/2f04ca7046b8442f8187e1672ef3f3ce.png?resizew=40)
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