1 . 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
在其定义域内是减函数”是真命题;
②命题“若
,则
”的否命题是“若
,则
”;
③命题“若x,y都是偶数,则
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/f12be5e0c1681b2f57e60a3fb0113b80.png)
②命题“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b4d795709b0abcf47bceec2250f2f9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3019b662e5dc2750bb6f9199d3250f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20849c00c47cbdc43f18d53341b6c4e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9eae9ba258299eb489b490594397e23c.png)
③命题“若x,y都是偶数,则
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b88584cf1df43e28d03592c7998b1653.png)
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
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
”是真命题;
②命题“若
,则
”的否命题是“若
,则
”;
③命题“若
,
都是偶数,则
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/c6455e38ff53ede2508e4d9cb23f0b86.png)
②命题“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b4d795709b0abcf47bceec2250f2f9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3019b662e5dc2750bb6f9199d3250f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20849c00c47cbdc43f18d53341b6c4e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9eae9ba258299eb489b490594397e23c.png)
③命题“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b88584cf1df43e28d03592c7998b1653.png)
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
名校
3 . 给出下列说法:
①“若
,则
”的逆命题是假命题;
②“在△ABC中,
是
的充要条件”是真命题;
③
或
是
的充分不必要条件;
④命题“若
,则
”的否命题为“若
,则
”.以上说法正确的是________ (填序号).
①“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58ab5174edcf796e06fc85e28614432f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eba75ca4ac87c18b45b5f420105f91f9.png)
②“在△ABC中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7725ad5bc8a8233f59ad3c4ccd7f465.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5aa3638653a94a02420f176d860e294e.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b4ad6bf033c2de624a30b57402f9142.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4738addce8080691ea629f831fcd17fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c47201a8f3f02096fd76b6a9b22680f.png)
④命题“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7da6d82d173ad18cc040e94c925b5ab9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0b051e1329de07b78b173b7980ea8ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/629507dcfdeb6866da428c4f45e2b21d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb6b1fc85c324b4c4defdc8f1012d9ee.png)
您最近一年使用:0次