1 . 已知D,E,F分别为△ABC的边BC,CA,AB的中点,且
,
,给出下列命题:①
; ②
; ③
,④![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1641db11de550beadd0dbc68e387052f.png)
其中正确命题的序号为________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7009c25899887e6df12cbc80034cb39f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c84eca96d76aebf52827bb14b41c22fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2edf77a4ba67a31d5d37f8e8c08fadae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfd878e4a202aed5cb1cf20541c85ed5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c55733f82695eff7f2286cd3d9d2f70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1641db11de550beadd0dbc68e387052f.png)
其中正确命题的序号为
您最近一年使用:0次
2 . 如图所示,点P在由线段AB,AC的延长线及线段BC围成的阴影区域内(不含边界),则下列说法中正确的是__________ .(填写所有正确说法的序号)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/d9fc9baf-f9fc-4bf6-8df2-131b375ed00b.jpg?resizew=182)
①存在点P,使得
;
②存在点P,使得
;
③存在点P,使得
;
④存在点P,使得
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/d9fc9baf-f9fc-4bf6-8df2-131b375ed00b.jpg?resizew=182)
①存在点P,使得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c60f47c0679c35ab9380bc788973637.png)
②存在点P,使得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afea9691c35520eca10232fe691b8c8d.png)
③存在点P,使得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47e90e7c8536143c8d1d883d86a3e7ae.png)
④存在点P,使得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f4c9b1e7c8bb335153e2ebf69c8ef2.png)
您最近一年使用:0次
名校
3 . 下列说法正确的是_________ (请把你认为正确说法的序号都填上).
(1)函数
的最小正周期为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86ebba6ed1add0fe647c0226614b9290.png)
(2)若命题
:“
,使得
”,则
:“
,均有
”
(3)
中,
是
的充要条件;
(4)已知点N在
所在平面内,且
,则点N是
的重心;
(1)函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f8639eae0325866c58acd33302151d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86ebba6ed1add0fe647c0226614b9290.png)
(2)若命题
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1485a4756c56f1126b9825d5019d544c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/264dab145ceba44696a6ee63b1e1549d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ffc1bb9d53a27d484396ad74d6a26e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c780149aef1bd77162e85f7f8906a6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba1c77d129b56255baf3d76eb2a6c2ff.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19dc38d888741a1b2e95fe0773a48c38.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca51be437b1a97ca92aa1159ab71102c.png)
(4)已知点N在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/202f58538466612afcf186e5c65d9a05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
您最近一年使用:0次