1 . 某企业为一个高科技项目注入了启动资金1000万元,已知每年可获利25%,但由于竞争激烈,每年年底需从利润中抽取200万元资金进行科研、技术改造与广告投入,方能保持原有的利润增长率,设经过
年后,该项目的资金为
万元.
(1)求数列
的通项公式.
(2)求至少需经过多少年,该项目的资金才可以达到或超过翻两番(即为原来的4倍)的目标(取
);
(3)若
,
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)求至少需经过多少年,该项目的资金才可以达到或超过翻两番(即为原来的4倍)的目标(取
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41ac9e5e7b99b75b61851a6ec1459166.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9d4a838962be69dd381e0a359276fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5843bfbd680a89691b5ae7fe1e046016.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
您最近一年使用:0次