已知等差数列
的公差d > 0,且
是方程
的两根,
(1)求数列
通项公式;
(2)设
,数列
的前n项和为
,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8eedd5b5ba81010aa9f45afbe62fa77e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/623a7c85a642d4a0fe7b2459be36512a.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50a813139b92a24e1124ef96e3e485f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5737f1f9cad2471f3ca53241b25a1eb9.png)
更新时间:2016-12-03 20:38:34
|
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc33d79c18e3607d955295d08be1b800.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cef0c441b189b885badac47868ccf71.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
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名校
解题方法
【推荐2】已知等差数列
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