题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061550-44573.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061550-98180.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061550-44573.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061550-98180.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061551-34197.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061551-58543.png)
(1)求小迪解题的学习收益量
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061550-98180.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061550-44573.png)
(2)求小迪回顾反思的学习收益量
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061550-98180.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061550-44573.png)
(3)问小迪如何分配解题和回顾反思的时间,才能使这20分钟的学习收益总量最大?
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061551-66361.png)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061551-48556.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061551-30663.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061551-91272.png)
解得
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061551-10447.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061552-25397.png)
(2)由图2,当
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061552-18059.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061552-16890.png)
当
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061552-20379.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061553-11413.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061553-55421.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061553-42941.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061553-70372.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061553-93632.png)
当
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061554-69171.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061554-11124.png)
因此
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061554-94440.png)
(3)设小迪用于回顾反思的时间为
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061554-83802.png)
学习收益总量为
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061550-98180.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061555-46644.png)
当
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061552-18059.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061555-24167.png)
当
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061555-50148.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061555-43830.png)
当
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061554-69171.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061555-82440.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061550-98180.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061550-44573.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061556-22267.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061556-63862.png)
综上,当
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061555-50148.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061555-43830.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061556-91226.png)
答:小迪用于回顾反思的时间为3分钟,用于解题的时间为17分钟时,学习收益总量最大.
解析
(2)这是一个分段函数,第一段是二次函数,根据图象特征设出顶点式,再根据图象经过原点即得解析式,第二段是一个常数函数
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061554-11124.png)
根据“学习收益总量=解题的学习收益量+回顾反思的学习收益量”,分别在
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061552-18059.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061554-69171.png)
核心考点
试题【善于不断改进学习方法的小迪发现,对解题进行回顾反思,学习效果更好.某一天小迪有20分钟时间可用于学习.假设小迪用于解题的时间(单位:分钟)与学习收益量的关系如图】;主要考察你对二次函数定义等知识点的理解。[详细]
举一反三
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061546-67490.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061547-52772.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061547-17053.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061547-75138.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061547-49880.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061540-46388.png)
A.(-2,3) | B.(2,3) | C.(-2,-3) | D.(2,-3) |
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061537-56953.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061537-80242.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061537-16758.png)
A.![]() | B.![]() | C.![]() | D.![]() |
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061530-16604.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061530-85895.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061525-13246.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061525-90360.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061525-81028.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061526-35701.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061526-53553.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061526-43482.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191019/20191019061526-57019.png)
最新试题
- 1下列各句中,加粗的成语使用正确的一句是[ ]A.两人本来就有意见,经他一挑拨,就更成掎角之势,互不往来了。 B
- 2( ),=( )
- 3My brother and I were alone in our apartment. My parents had
- 4若-2010的绝对值是m,则下列结论正确的是( )A.m=2010B.m=12010C.m=-2010D.m=-120
- 5在千龙网上一网友发帖子说:“现在的年轻人学历越高,往往社交能力越差,一心埋在书本里和校园里,跟社会接触少,一些人从学校出
- 61947年夏,率领晋冀鲁豫解放军主力挺进大别山的是①彭德怀②贺龙③刘伯承④***[ ]A.①②B.①③C.②④D
- 7【题文】下列词语中加点的字的读音,全都正确的一组是
- 8(9分)海洋植物,如海带、海藻中含有丰富的碘元素,碘元素以碘离子的形式存在。实验室里从海带中提取碘的流程如下:(1)指出
- 9Edison ________ one of the greatest inventors in the worldA.
- 10某市统计局就本地居民的月收入调查了10000人,并根据所得数据画了样本的频率分布直方图(每个分组包括左端点,不包括右端点
热门考点
- 1---Can I tell my best friend about it? ---No. I don’t want a
- 2已知椭圆x2a2+y2b2=1(a>b>0)的离心率为22,椭圆上任意一点到右焦点F的距离的最大值为2+1.(I)求椭圆
- 3下列各句中,没有语病的一句是 [ ]A.《文学欣赏》以提高学生人文素质、拓宽学生文学视野、提升学生文学欣赏能力
- 4(11·台州)(12分)2011年5月19日,中国首个旅游日正式启动.某校组织了八年级800名学生参加的旅游地理知识竞赛
- 5选用人才既要有格又无格,拘泥于一格,会压制人才;没有一定的格,无法把握人才的标准,从哲学上说,就是①既要着重抓住事物的主
- 6若∠α的补角是105.5°,则∠α的余角是( )A.5.5°B.74.5°C.31°D.45°
- 7下列对于溶液中的问题叙述正确的是 [ ]A.向冰醋酸中加水至配成醋酸稀溶液的过程中,H+的浓度逐渐减小 B.对于
- 8(2013·高考重庆卷)Recycling is one way to protect the environment;
- 9中华民族是勤劳智慧的民族,在历史上创造了辉煌灿烂的文明,隋唐到两宋时期有很多成就领先世界。请同学门开动脑筋想一想有哪些?
- 10选择填空。Mr Wang is ______ old teacher. ______ is very strict. [