名校
解题方法
1 . 记数列
的前n项和分别为
,若
是等差数列,且
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62e567d7e9761951a266953c8d5042ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/478421b81927e435cbcf5acafa89efd7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36bfa6a943af45319bc82e33f78e2c1d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/681967bfbdcdae96320e06da896b4da4.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
A.![]() | B.![]() | C.![]() | D.![]() |