名校
1 . 有下列四个命题:
①命题“面积相等的三角形全等”的否命题;
②“若
,则
互为倒数”的逆命题;
③命题“若
,则
”的逆否命题;
④命题“若
则
有实根”的逆否命题.
其中是真命题的是________________ (填上你认为正确的命题的序号)
①命题“面积相等的三角形全等”的否命题;
②“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/377a2333ff8c63cbdb20b882d6d5a7ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/108d632eb62517afdf621b6d038e05e2.png)
③命题“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b05d2be27e8f53e4de3071846dffb41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2ad78dc8b8aed907b4fe9640c997454.png)
④命题“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44b2cd7d1ea7457dfcf18bd4ca032242.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8b21e18c6907fc354f7d4078fc0ea25.png)
其中是真命题的是
您最近一年使用:0次
2 . 给出下列命题:
①函数
既有极大值又有极小值,则
;
②若
,则
的单调递减区间为
;
③过点
可作圆
的两条切线,则实数
的取值范围为
;
④双曲线![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/8954766a6bc94675b36f786f8c559743.png?resizew=81)
的离心率为
,双曲线
的离心率为
,则
的最小值为
.
其中为真命题的序号是_____________ .
①函数
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/b4f9c0a5a9914e9eb9fb42efd72c85fe.png?resizew=156)
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/f489fbca5a3e4dafb9f11b89313ba609.png?resizew=84)
②若
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/95003f26be3649b8b030792a266e24ae.png?resizew=116)
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/002681d95def4157bc7a27c306fd8e5e.png?resizew=36)
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/3a12f79d04394166b7dde83c658627df.png?resizew=45)
③过点
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/26883c75e895441082541357ef5c859d.png?resizew=49)
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/83157d01896544de928d63a4199e7273.png?resizew=199)
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/f419ee9e792f4cddb3207acec26a56ab.png?resizew=13)
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/f98c1ee6643843f9a3f07756afc5ab6d.png?resizew=91)
④双曲线
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/8954766a6bc94675b36f786f8c559743.png?resizew=81)
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/27d83082b5264337a57ebadb1ec7b11d.png?resizew=85)
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/7ae6201495f143bab37f0f7e1d8f50e0.png?resizew=16)
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/01fcd2d3da2244d4b1ba22373b7c0129.png?resizew=81)
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/70f4621339394a12bace5c8c955aa087.png?resizew=17)
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/f238b5e178f845e0a29c40462ebfd9a2.png?resizew=45)
![](https://img.xkw.com/dksih/QBM/2016/5/13/1572635889983488/1572635896193024/STEM/86c79330e8f64b95912269031c598cf7.png?resizew=33)
其中为真命题的序号是
您最近一年使用:0次