解题方法
1 . 已知等比数列
的各项都为正数,
,
,数列
的首项为
,且前
项和为
,再从下面①②③中选择一个作为条件,判断是否存在
,使得
,
恒成立?若存在,求出
的值;若不存在,说明理由.
①
;②
,
;③
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c73e06605cc93d9844b02ca51e90433e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70c27d4f93149f5535c1f30f06195e68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24431f390ba671b4de0d6abaeb9cf476.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bde2576b383ae3c851529435805b3adc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e115bb8c62b170a5609c4532782ece99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a16e11c4ef06268cd1dd63432dc4924.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d94a522caa2d761de2ae60149b5c2e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ee45219629dd30af171588e646f8b12.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/802b3253f4c63d6bfb1320234397201e.png)
您最近一年使用:0次
2023-01-06更新
|
582次组卷
|
3卷引用:四川省绵阳市2023届高三上学期第二次诊断性测试理科数学试题
21-22高三上·上海浦东新·期中
名校
解题方法
2 . 贾先生买了一套总价为
万元的商品房,首付
万元,其余
万元(本金)向银行申请贷款,贷款月利率
.从贷款后的第一个月后开始还款(即第一次还款日距贷款发放日正好一个月),
年还清.(精确到
元)
(1)若每月等额偿还本金(
万元),则贷款利息随本金逐月递减,还款额也逐月递减,其计算方法是:每月还款金额
(贷款本金/还款月数)
(本金
已归还本金累计额)
每月利率,请计算第
个月还款金额是多少元?
(2)为图方便,若每月还款金额相等,问每月应还款多少元?(注:如果上个月欠银行贷款
元,则一个月后,应还给银行固定数额
元,此时贷款余额为
元)
(3)请问
年后还清贷款时,用这两种不同还款方式归还贷款,实际还款总额分别是多少元?(不考虑时间价值等因素).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47543f9c51eb71b208b483444a4cff58.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b685c556cc423e4833c1dc671a134cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c6bf2782515ceceb1503a845446ad7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f58b9b382aa6c0bb3d4967f13ca9b56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b53c7539ed297ea63b9ace6f5cc58ca8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
(1)若每月等额偿还本金(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c6bf2782515ceceb1503a845446ad7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6706fe00b4e231e62d9ecbec567d526b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d4cd9a7068de096606d1ab991f5e6da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bfc339cf6dd66599db64fa3fa44e608.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2468403b3eba9e40bfa36f464e927738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
(2)为图方便,若每月还款金额相等,问每月应还款多少元?(注:如果上个月欠银行贷款
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1e165d6b0dfbe3fbe66486ee4e152d0.png)
(3)请问
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b53c7539ed297ea63b9ace6f5cc58ca8.png)
您最近一年使用:0次
3 . 已知等比数列
的前
项和为
,且
.
(1)求
;
(2)定义
为取整数
的个位数,如
,求
的值 .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6b981758450e9dcee6cfbe6c67c61f8.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
(2)定义
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2ab85825d4a002600ca41bd3cd2ee7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1939710991647ab22cb5dff165b0c738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e812b69c7dc1bf485eed487a1cafe015.png)
您最近一年使用:0次
2021-06-03更新
|
707次组卷
|
3卷引用:重庆市长寿中学校2021届高三下学期5月考前模拟数学试题