1 . 已知命题
;
.
(1)若
,写出命题“若
则
”的逆否命题,并判断真假;
(2)若
是
的充分不必要条件,求实数
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52e37a4ac519b313ee0c91ab75b37270.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f1322eaaebbe6b54b72515e3603cd02.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.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/9aa8a716a31b0f51b70fdf9bdb257909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
您最近一年使用:0次
2021-01-28更新
|
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|
2卷引用:山西省太原市2020-2021学年高二上学期期末数学(理)试题
名校
2 . 命题“若|a|=|b|,则a=b或a=﹣b”的逆否命题是_____ .
您最近一年使用:0次
2020-01-04更新
|
177次组卷
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4卷引用:山西省临汾一中、翼城中学、曲沃中学等学校2018-2019学年高二上学期期末数学(文)试题
11-12高二下·湖北武汉·期中
名校
3 . 命题“若
,则
”以及它的逆命题,否命题,逆否命题中,真命题的个数为.
![](https://img.xkw.com/dksih/QBM/2014/11/4/1571889228546048/1571889234051072/STEM/9f8bf50420fd498e93e5c38ed3d795c1.png)
![](https://img.xkw.com/dksih/QBM/2014/11/4/1571889228546048/1571889234051072/STEM/0e5d5351e24a47289730fc5ab267bfc8.png)
A.1 | B.2 | C.3 | D.4 |
您最近一年使用:0次
2016-12-03更新
|
829次组卷
|
10卷引用:山西省怀仁市重点中学2019-2020学年高二上学期期末考试数学(理)试题
山西省怀仁市重点中学2019-2020学年高二上学期期末考试数学(理)试题(已下线)2011-2012年云南景洪第一中学高二上期末考试理科数学试卷2016-2017学年内蒙古集宁一中高二上学期期末考试数学(文)试卷(已下线)2011-2012学年湖北武汉部分重点中学(五校)高二下期中文科数学卷(已下线)2014-2015学年湖南省益阳市箴言中学高二9月月考文科数学试卷2015-2016学年北大附中河南分校高一宏志班下期中数学卷2015-2016学年湖北省孝感高中高二5月调考文科数学试卷(已下线)2019高考备考一轮复习精品资料 【文】专题二 命题及其关系 押题专练(已下线)2019高考热点题型和提分秘籍 【文数】专题2 命题及其关系、充分条件与必要条件 (题型专练)福建省厦门市2019-2020学年高二上学期阶段性质量检测数学试题
4 . 下列四个命题:
①“若xy=0,则x=0且y=0”的逆否命题;②“正方形是菱形”的否命题;③若
;④“若tana=tanb,则a=b”的逆命题;.其中真命题为_______________ (只写正确命题的序号).
①“若xy=0,则x=0且y=0”的逆否命题;②“正方形是菱形”的否命题;③若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0768764cb3fb0383a24ae04ad6dd358.png)
您最近一年使用:0次
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|
240次组卷
|
2卷引用:2015-2016学年山西省孝义市高二上学期期末考试理科数学试卷
5 . 下列命题中,真命题是
A.∀x∈R,x2≥x |
B.命题“若x=1,则x2=1”的逆命题 |
C.∃x∈R,x2≥x |
D.命题“若x≠y,则sinx≠siny”的逆否命题 |
您最近一年使用:0次
6 . 下列命题中正确命题的个数是( )
①命题“若
,则
”的逆否命题为“若
,则
”;
②“
”是“
”的必要不充分条件;
③若
为假命题,则
均为假命题;
④命题![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51441c8788ff11be766766227793246d.png)
,使得
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99e600d9843ce406c441b402837d0388.png)
,都有
.
①命题“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1fdf7d28b97fb6fe731703f80e122ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b384412acba251d87902ab928902f16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e30c903d8f8a05332af0b19e7e40df3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a8a2a94168af9b16ce89271a5d8dc6b.png)
②“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20849c00c47cbdc43f18d53341b6c4e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e0d1099bdcf2619088c490c1abc4537.png)
③若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c13472bf0353e16784a22e1f890fba40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cd5371a6f0f82c65dd22f75f8b807c1.png)
④命题
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51441c8788ff11be766766227793246d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2939abf9f1755ea304eeb1e73063cba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03551548269a42fbe818d3426ffa8586.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99e600d9843ce406c441b402837d0388.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ad5fe274cfc8da2dacfb65801f344ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba1c77d129b56255baf3d76eb2a6c2ff.png)
A.1 | B.2 | C.3 | D.4 |
您最近一年使用:0次
7 . ①命题“若
,则
”的逆否命题为:“若
,则
”.
②“
”是“
”的充要条件;
③若
为假命题,则
均为假命题.
④对于命题
:
,
, 则
:
,
.
上面四个命题中正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1fdf7d28b97fb6fe731703f80e122ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b384412acba251d87902ab928902f16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e30c903d8f8a05332af0b19e7e40df3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a8a2a94168af9b16ce89271a5d8dc6b.png)
②“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b384412acba251d87902ab928902f16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37b0b55c3297ce66c96d1559d76971f4.png)
③若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c13472bf0353e16784a22e1f890fba40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cd5371a6f0f82c65dd22f75f8b807c1.png)
④对于命题
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2939abf9f1755ea304eeb1e73063cba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c5623033629495668207179c408c4b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98b5effca87ab4aafa3bc054d9a58b36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ad5fe274cfc8da2dacfb65801f344ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/491ef2ec844032e0c2ab9cc4a545dff3.png)
上面四个命题中正确的是( )
A.①② | B.②③ | C.①④ | D.③④ |
您最近一年使用:0次
2016-12-04更新
|
829次组卷
|
2卷引用:2015-2016学年山西太原五中高二上学期期末理科数学试卷