1 . 已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
和
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d51f9147b8265c0276c1f2c2659197.png)
的等差中项是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd3304e23f3b0f9569c4140ca89b6498.png)
,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fad491e5b5e14c49ef8b7004ebcfcef9.png)
和
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
的等差中项是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d07ae0b4264da6a8812454ffd2f20d94.png)
,则
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
和
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
的等差中项是
2018-09-17更新
|
547次组卷
|
2卷引用:2018年9月7日 《每日一题》人教必修5-等差中项(已下线)2018年9月7日 《每日一题》人教必修5-等差中项(已下线)2019年9月6日《每日一题》 必修5 等差中项
2 . 已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
是等差数列,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
是其前
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
项和,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ab3781dc167cf1cf03315c6de6ebb5a.png)
,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea5cc09a66cb35ef1ee5fce4dd3da8ca.png)
,则
________.
2018-10-09更新
|
363次组卷
|
1卷引用:2018年9月13日 《每日一题》人教必修5-等差数列的前n项和(1)(已下线)2018年9月13日 《每日一题》人教必修5-等差数列的前n项和(1)