名校
1 . 有下列四个说法:
①已知向量
,
,若
与
的夹角为钝角,则
;
②若函数
的图像关于直线
对称,则
;
③当
时,函数
有四个零点;
④函数
在
上单调递减,在
上单调递增.
其中正确的是________ (填上所有正确说法的序号)
①已知向量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80d769ab21af5365d3c00dc617375ce4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91764e19d4a8e0bc0624287b73fb39df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a2f4b1178f68bd147d1a2a6acd04435.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c94075193c11fe43f2396cff5a485054.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65d1eec645764636c0e23b05e8f93234.png)
②若函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09e28a908a083449f14499fbc58ba6f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24db7b603aebdee8e298d1fe49c848e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb52d91a9b9e084e6e4f0aa0a4a1bd96.png)
③当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fbc7b35682426aab8bd896a9ce35a81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb4f2ac7aae8926f5741a7f1b12552a4.png)
④函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1947fd8b1e5fa9096c13256fdb3a23ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e4b97703638756a4051a3dd0cdcf5a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18c9aeed3c8c5a04e48d011c607f9142.png)
其中正确的是
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