解题方法
1 . 某公司计划从甲、乙两种方案中选择一种方案,进行广告宣传拓展业务.市场调研表明,采用甲方案的宣传费用
(单位:十万元)与其利润
(单位:百万元)之间的关系是
,乙方案的宣传费用
(单位:十万元)与其利润
(单位:百万元)之间的关系是
,对于
,用
表示
,
中的最大者,记为
.
(1)求
的解析式;
(2)已知该公司的宣传费用预算为
(单位:十万元),以利润为决策依据,请问该公司应投入多少宣传费用
(单位:十万元)?并求出相应的利润
(单位:百万元).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2577b45245cb355b9eb39bc9970eae8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4669810732b633b60dbeaf0bf57204f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bab3232b625de4d7212e6773500ddcd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3add1679c27392a1a7f635723a4b36eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3859cd3de4d6d485df050b0f5321d6c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4669810732b633b60dbeaf0bf57204f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c065dc2782f5e5a662df2ea357b9c31.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3859cd3de4d6d485df050b0f5321d6c6.png)
(2)已知该公司的宣传费用预算为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f93a232c88870d213a7b74a796a1ff4b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5451e80dbfda746223d73cc0a26e220a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
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名校
2 . 某环线地铁按内、外线同时运行,内、外环线的长均为30千米(忽略内、外环线长度差异),新调整的方案要求内环线列车平均速度为20千米/小时,外环线列车平均速度为30千米/小时,现内、外环线共有18列列车全部投入运行,其中内环投入
列列车.
(1)写出内、外环线乘客的最长候车时间(分钟)分别关于
的函数解析式;
(2)要使内、外环线乘客的最长候车时间之差距不超过1分钟,问内、外环线应各投入几列列车运行?
(3)要使内、外环线乘客的最长候车时间之和最小,问内、外环线应各投入几列列车运行?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(1)写出内、外环线乘客的最长候车时间(分钟)分别关于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(2)要使内、外环线乘客的最长候车时间之差距不超过1分钟,问内、外环线应各投入几列列车运行?
(3)要使内、外环线乘客的最长候车时间之和最小,问内、外环线应各投入几列列车运行?
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2019高三·全国·专题练习
3 . 设函数
定义域为
若
在
上单调递减,则称
为函数
的峰点,
为含峰函数.(特别地,若
在
上单调递增或递减,则峰点为1或0).
对于不易直接求出峰点
的含峰函数,可通过做试验的方法给出
的近似值,试验原理为:“对任意的
若
则
为含峰区间,此时称
为近似峰点;若
则
为含峰区间,此时称
为近似峰点”.
我们把近似峰点与
之间可能出现的最大距离称为试验的“预计误差”,记为
,其值为
其中
表示
中较大的数![](https://staticzujuan.xkw.com/quesimg/Upload/formula/913b7537e011acfeec11952731351388.png)
(1)若
求此试验的预计误差
;
(2)如何选取
才能使这个试验方案的预计误差达到最小?并证明你的结论(只证明
的取值即可).
(3)选取
可以确定含峰区间为
或
在所得的含峰区间内选取
,由
与
或
与
类似地可以进一步得到一个新的预计误差
.分别求出当
和
时预计误差
的最小值.(本问只写结果,不必证明)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/879757d166a223273732cdd16523a523.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fb3864c16b678e771cea1982f0597f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8b2c4bffa1b91fe840b66855f11a6d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e11f4ca0e7ace69f92130d0525bcdb3.png)
对于不易直接求出峰点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8b2c4bffa1b91fe840b66855f11a6d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8b2c4bffa1b91fe840b66855f11a6d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8726a6d8e18521de2860c1569ce45140.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10b86a95482b0076f1b4318c2b8e2478.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9bacfb2ce7a563ef6012537e0dcb80b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/038e777c5ee125e0f1377463421a36f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3578b4efca76ca9f2a3d1d96508064bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
我们把近似峰点与
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8b2c4bffa1b91fe840b66855f11a6d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be8ae71bfead3529d50ad0f58a22d20f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03049a2f3be286f52c971144a37781c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b0fffbec1fe851795dfdd448bf0d165.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/913b7537e011acfeec11952731351388.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f548b5c48a34a72f99fe4c2ef7cad8b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
(2)如何选取
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c58cc80f792a9262c4da33fabd21e95.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
(3)选取
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8726a6d8e18521de2860c1569ce45140.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9bacfb2ce7a563ef6012537e0dcb80b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97a3051e86a412ecb19b7555f82ac08e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/291c25fc6a69d6d0ccfb8d839b9b4462.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/291c25fc6a69d6d0ccfb8d839b9b4462.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/291c25fc6a69d6d0ccfb8d839b9b4462.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b19708dcc01886c314e904d8eed8d81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/865afa1f97658d54e0616094b6a6aee1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54802791b3480fcd7f345d21b642559b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b19708dcc01886c314e904d8eed8d81.png)
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