名校
1 . 下列命题:①
;②
;③
;④
若
,则
的否命题,其中正确的结论是______ .(填写所有正确的序号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bbc63eddf227cef3226d09b7ac033b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/405aa2b3947169fedd0c8af169fcbc8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1279a34f2bb9809633487d47b5383c09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/853bd348db38586386c3cfaf9edfde6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9eae9ba258299eb489b490594397e23c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20849c00c47cbdc43f18d53341b6c4e5.png)
您最近一年使用:0次
2020-11-21更新
|
1092次组卷
|
5卷引用:四川省凉山彝族自治州冕宁中学校2020-2021学年高二上学期期中数学(理科)试题
2 . 以下关于命题的说法正确的有________ (填写所有正确命题的序号).
①“若
,则函数![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f45afdf4d717bb03adac6b899c367acb.png)
在其定义域内是减函数”是真命题;
②命题“若a=0,则ab=0”的否命题是“若a≠0,则ab≠0”;
③命题“若x,y都是偶数,则x+y也是偶数”的逆命题为真命题;
④命题“若
,则
”与命题“若
,则
”等价.
①“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba2c58e340ebcea00ef2a6d05a836301.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f45afdf4d717bb03adac6b899c367acb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37b93abe2a497b7ef3cb8c1b9de8492e.png)
②命题“若a=0,则ab=0”的否命题是“若a≠0,则ab≠0”;
③命题“若x,y都是偶数,则x+y也是偶数”的逆命题为真命题;
④命题“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/582ad43edf388c096e7704d92340bf75.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5286186cb58bf265a2a96e5195d88d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dab92728b35ed5798e07a2b0095bfcc1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a27dd329517f0dd8f1d0dfade6138ed4.png)
您最近一年使用:0次