1 . 给出下列四个命题:
①“若
,则
”的逆命题;
②“若数列
是等比数列,则
”的否命题;
③“若
,则关于x的方程
有实根”的逆命题;
④“若
,则
”的逆否命题.
其中真命题的个数是________ .
①“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/876e70d783ca1eece5c546f0ad708358.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d0ea3acd83c2a33956fe4b57bc4542c.png)
②“若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be02544e0fb9b80e2ce723bcc697da93.png)
③“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c56485f5459cbead897ee5f874f249c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e232f45482195a9500e067fe9f970af0.png)
④“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04ceb1f338fa60976229d7ec6531b626.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/caf22d7d1a965bda25168a233fb6290c.png)
其中真命题的个数是
您最近一年使用:0次
名校
2 . 给出如下四个命题:①把二进制数
化为十进制数,结果为
;②将一组数据中的每个数据都加上或减去同一个常数后,平均值不变,方差不变;③从装有完全相同的
个红球和
个黄球的盒子中任取
个小球,则事件“至多一个红球”与“都是红球”互斥且对立;④若“
”为假命题,则
、
均为假命题.其中正确的命题的序号是________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d2833861a60f7bb3e6f2bdd148e7a83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e595b1cc755cf0dd076e91cf9e9a3e5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c13472bf0353e16784a22e1f890fba40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
您最近一年使用:0次
2020-11-12更新
|
176次组卷
|
2卷引用:广西贵港高中2020-2021学年高二上学期理科期中教学质量监测试题
3 . 给出下列四个命题:
①
,
;
②当
时,
,
;
③
成立的充要条件是
;
④“
”是“
”的必要不充分条件.
其中真命题的个数是( )
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c780149aef1bd77162e85f7f8906a6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/547adc121c442b3bb9189e6df5ee4018.png)
②当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30f2e8b5365c2f086a02e5dd3c3bd116.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1485a4756c56f1126b9825d5019d544c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdb2d6c85141c595c22ebd713b42086d.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f059b886d87517821b5ed0740745b13a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8efd32ba5030535598e979fd6d3a4d5c.png)
④“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2b13d3854ea2671a9ae5be5b69a573e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25e69d706e31a35a06b489423d5e9e02.png)
其中真命题的个数是( )
A.1 | B.2 | C.3 | D.4 |
您最近一年使用:0次
2020-03-13更新
|
264次组卷
|
2卷引用:广西壮族自治区贵港市桂平市2019-2020学年高二上学期期中数学试题