1 . 对下列命题的否定,其中说法不正确的是( )
A.![]() ![]() ![]() |
B.![]() ![]() |
C.![]() ![]() |
D.![]() ![]() ![]() ![]() |
您最近一年使用:0次
名校
2 . 给出如下四个命题:
①“抛物线
的焦点坐标是
”为真命题;
②若
:
,则
:
;
③“
,
”的否定是“
,
”;
④“任意
,
”为真命题的一个充分不必要条件是
.
其中不正确的命题的是___________ .
①“抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b1183df9f26985febdc844cda75ed4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d7a999c36de5c9a9ce876a4a56fa34c.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0483b89034216f8684241e66e7942d4b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4034672c4968a0607d04f8b6d0c0627a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1940991107dc6ae92d8fa19df561e508.png)
③“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc906b12f576e3ffc5e74d3d50c2bbac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6935a13445cd10752d10072d9ad4f188.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d009c9bd0a09d83c817b3bef8ef8351e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2fc142a1a27251086b668c77bfebf65.png)
④“任意
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0eac2b31a19918895e5af2d316490e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee9815fddd14a70e4786a3b608876b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f184ef9e0d57554e95f369c9d4bbfea1.png)
其中不正确的命题的是
您最近一年使用:0次
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3 . 给出如下四个命题:其中不正确的命题的个数是( )
①若“
且
”为假命题,则
、
均为假命题;
②若
:
,则
:
;
③“
,
”的否定是“
,
”;
④任意“
,
”为真命题的一个充分不必要条件是
.
①若“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0483b89034216f8684241e66e7942d4b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4034672c4968a0607d04f8b6d0c0627a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1940991107dc6ae92d8fa19df561e508.png)
③“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc906b12f576e3ffc5e74d3d50c2bbac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6935a13445cd10752d10072d9ad4f188.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d009c9bd0a09d83c817b3bef8ef8351e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2fc142a1a27251086b668c77bfebf65.png)
④任意“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0eac2b31a19918895e5af2d316490e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee9815fddd14a70e4786a3b608876b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f184ef9e0d57554e95f369c9d4bbfea1.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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4 . (多选)对下列命题的否定,其中说法正确的是( )
A.p:∀x≥3,x2-2x-3≥0;p的否定:∃x≥3,x2-2x-3<0 |
B.p:存在一个四边形的四个顶点不共圆;p的否定:每一个四边形的四个顶点共圆 |
C.p:有的三角形为正三角形;p的否定:所有的三角形不都是正三角形 |
D.p:∃x∈R,x2+2x+2≤0;p的否定:∀x∈R,x2+2x+2>0 |
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