名校
1 . 已知各项不为0的等差数列
满足
,数列
是等比数列且
,则
等于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/950bef0ee17c25bed6689e242dc4176f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd9c77ce4d6b6f7c75a8b84b5c3c6c0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec0dbda699c3079178016f05a01b8ce1.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2017-08-18更新
|
2134次组卷
|
9卷引用:2017年山西重点中学协作体高三暑假联考文科数学
解题方法
2 . 已知数列
的各项排成如图所示的三角形数阵,数阵中每一行的第一个数
构成等差数列
,
是
的前
项和,且
,
.
![](https://img.xkw.com/dksih/QBM/2017/8/17/1754071308828672/1754135332839424/STEM/26588309940b449f8db351f4a4ffa304.png?resizew=222)
(1)若数阵中从第3行开始每行中的数按从左到右的顺序均构成公比为正数的等比数列,且公比相等,已知
,求
的值;
(2)设
,当
时,对任意
,不等式
恒成立,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/441cf722a27112079abeb4d0954b81c0.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/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81b1a669907dfdd9a1c6aa976c000f56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fca2cc2768794136c1e4da47d2f0873e.png)
![](https://img.xkw.com/dksih/QBM/2017/8/17/1754071308828672/1754135332839424/STEM/26588309940b449f8db351f4a4ffa304.png?resizew=222)
(1)若数阵中从第3行开始每行中的数按从左到右的顺序均构成公比为正数的等比数列,且公比相等,已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a37c2ec7c09f42c1a255cf19057f8a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecfce7a88a7bf35de6a85fb20b56be8a.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c595a50345424ae966e8db73e21907ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c395021157c73ac8dcde32864f7e121.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e145b6046bc80d0ffecc61ac67c87ca1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bbc8b6df4160448c0fd04d7de64468a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
您最近一年使用:0次
解题方法
3 . 在
中,
分别为
的对边,若
,
,且
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ccd4162c7d09f970cb77cadacdbe521.png)
__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/febfce52f76b851da3c3dda7ef205a12.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7a74c3e9a8f3f11e98b4fa659a97679.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a12562e286e953b3f2de429fa99b501c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ccd4162c7d09f970cb77cadacdbe521.png)
您最近一年使用:0次
解题方法
4 . 已知
,则
的最小值是__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0589addad4a958dbf773960c421699e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cc6a7f85c85613d4cf24f3cd26d209d.png)
您最近一年使用:0次
2016-12-04更新
|
241次组卷
|
2卷引用:2017年山西重点中学协作体高三暑假联考文科数学
名校
5 . 在
中,
.
(Ⅰ)若
,求
的大小;
(Ⅱ)若
,求
的面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ca890db371750d26ec7f049cfe4f714.png)
(Ⅰ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51c3a1f1a37e69b2dc06bf0affd58f22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/febc9a89d0d1c97b88c0f4acd32b4e67.png)
(Ⅱ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ba1b919b44c9e1ae938d423d8ed9b7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
您最近一年使用:0次
2016-12-03更新
|
926次组卷
|
6卷引用:2017年山西重点中学协作体高三暑假联考文科数学