1 . 判断下列数列是否为等比数列:
(1)9,0.9,0.09,0.009;
(2)
,
,
,
;
(3)
,
,
,
;
(4)
,
,
,
.
(1)9,0.9,0.09,0.009;
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4b57c4a905b766f8755d01b28d22a63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/993908fc9c1baaf8774ba080107c23d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dd7d7624d5efbb189205bd3a4a13e3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9bac900bd09df30926bbf18dcf94628a.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5498db3231db49529b93fdf13433298a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65f5ca7640f5202cc27dd03190d101e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc6e41b8e683c5d3b71c867b582524a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09a9b9cada684621f0b080058a3582d3.png)
(4)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef25f1fa9539e95e763cd0ef4bf68782.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63b4d1868e26d04a2bd6b30a07d514c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d3e49942ad60434e5ea393f722be9be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/425c4c772403a5d629255d864fe9abf4.png)
您最近一年使用:0次
21-22高二·江苏·课后作业
2 . 判断下列数列是否为等比数列:
(1)1,2,1,2,1;
(2)-2,-2,-2,-2;
(3)1,
,
,
,
;
(4)2,1,
,
,0;
(5)
,
,
;
(6)1,-1,1,-1.
(1)1,2,1,2,1;
(2)-2,-2,-2,-2;
(3)1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f30d314a642667fef559032264647366.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/158b045c6172c4178d7aa52083e1489f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4924aedda5d82685e31b85516e7105a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54da42446de9129bc86246497e676eaa.png)
(4)2,1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56d266a04f3dc7483eddbc26c5e487db.png)
(5)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47beab88f3c7978932f2e13824d60191.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/930f7706c8f0a021d2e81f1cba24cca0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c706203c5897e3e5cf328b8b35cc3ef.png)
(6)1,-1,1,-1.
您最近一年使用:0次
3 . 已知一个等比数列
的首项为
,公比为q.
(1)将
的前m项去掉,其余各项依次构成的数列还是等比数列吗?如果是,它的首项与公比分别为多少?
(2)取出
的所有奇数项,依次构成一个新的数列,这个数列还是等比数列吗?如果是,它的首项与公比分别为多少?
(3)取出
的所有项数为5的倍数的各项,依次构成一个新的数列,这个数列还是等比数列吗?如果是,给出证明并求出首项与公比;如果不是,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
(1)将
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)取出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(3)取出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
您最近一年使用:0次
4 . 存在数列既是等差数列又是等比数列吗?如果存在,试举出实例;如果不存在,说明理由.
您最近一年使用:0次
5 . 已知一个正三角形边长为a,以此正三角形的高为边作第二个正三角形,依此类推继续作正三角形.求前10个正三角形的周长之和.
您最近一年使用:0次
6 . 某林场计划第一年造林15公顷,以后每年比前一年多造林20%,该林场5年共造林多少公顷?
您最近一年使用:0次
20-21高二·全国·课后作业
7 . 某制糖厂第一年制糖5万吨.如果平均每年的产量比上一年增加10%,那么从第一年起,约几年内可使总产量达到30万吨(保留到个位)?(参考数据:
.)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bcea73811a794f4e4ef9f140e76784a9.png)
您最近一年使用:0次