温故知新 1.离散型随机变量的定义可能取值为有限个或可以一一列举的随机变量,我们称为离散型随机变量.通常用大写英文字母表示随机变量,例如X,Y,Z;用小写英文字母表示随机变量的取值,例如x,y,z.随机变量的特点: 试验之前可以判断其可能出现的所有值,在试验之前不可能确定取何值;可以用数字表示2、随机变量的分类①离散型随机变量:X的取值可一、一列出;②连续型随机变量:X可以取某个区间内的一切值随机变量将随机事件的结果数量化.3、古典概型:①试验中所有可能出现的基本事件只有有限个;②每个基本事件出现的可能性相等。二、探究新知探究1.抛掷一枚骰子,所得的点数X有哪些值?取每个值的概率是多少? 因为X取值范围是{1,2,3,4,5,6}而且"P(X=m)"=1/6,m=1,2,3,4,5,6.因此X分布列如下表所示
一、情境导学我国著名数学家吴文俊先生在《数学教育现代化问题》中指出:“数学研究数量关系与空间形式,简单讲就是形与数,欧几里得几何体系的特点是排除了数量关系,对于研究空间形式,你要真正的‘腾飞’,不通过数量关系,我想不出有什么好的办法…….”吴文俊先生明确地指出中学几何的“腾飞”是“数量化”,也就是坐标系的引入,使得几何问题“代数化”,为了使得空间几何“代数化”,我们引入了坐标及其运算.二、探究新知一、空间直角坐标系与坐标表示1.空间直角坐标系在空间选定一点O和一个单位正交基底{i,j,k},以点O为原点,分别以i,j,k的方向为正方向、以它们的长为单位长度建立三条数轴:x轴、y轴、z轴,它们都叫做坐标轴.这时我们就建立了一个空间直角坐标系Oxyz,O叫做原点,i,j,k都叫做坐标向量,通过每两个坐标轴的平面叫做坐标平面,分别称为Oxy平面,Oyz平面,Ozx平面.
一、 问题导学前面两节所讨论的变量,如人的身高、树的胸径、树的高度、短跑100m世界纪录和创纪录的时间等,都是数值变量,数值变量的取值为实数.其大小和运算都有实际含义.在现实生活中,人们经常需要回答一定范围内的两种现象或性质之间是否存在关联性或相互影响的问题.例如,就读不同学校是否对学生的成绩有影响,不同班级学生用于体育锻炼的时间是否有差别,吸烟是否会增加患肺癌的风险,等等,本节将要学习的独立性检验方法为我们提供了解决这类问题的方案。在讨论上述问题时,为了表述方便,我们经常会使用一种特殊的随机变量,以区别不同的现象或性质,这类随机变量称为分类变量.分类变量的取值可以用实数表示,例如,学生所在的班级可以用1,2,3等表示,男性、女性可以用1,0表示,等等.在很多时候,这些数值只作为编号使用,并没有通常的大小和运算意义,本节我们主要讨论取值于{0,1}的分类变量的关联性问题.
4.写出下列随机变量可能取的值,并说明随机变量所取的值表示的随机试验的结果.(1)一个袋中装有8个红球,3个白球,从中任取5个球,其中所含白球的个数为X.(2)一个袋中有5个同样大小的黑球,编号为1,2,3,4,5,从中任取3个球,取出的球的最大号码记为X.(3). 在本例(1)条件下,规定取出一个红球赢2元,而每取出一个白球输1元,以ξ表示赢得的钱数,结果如何?[解] (1)X可取0,1,2,3.X=0表示取5个球全是红球;X=1表示取1个白球,4个红球;X=2表示取2个白球,3个红球;X=3表示取3个白球,2个红球.(2)X可取3,4,5.X=3表示取出的球编号为1,2,3;X=4表示取出的球编号为1,2,4;1,3,4或2,3,4.X=5表示取出的球编号为1,2,5;1,3,5;1,4,5;2,3,5;2,4,5或3,4,5.(3) ξ=10表示取5个球全是红球;ξ=7表示取1个白球,4个红球;ξ=4表示取2个白球,3个红球;ξ=1表示取3个白球,2个红球.
本节课选自《2019人教A版高中数学选择性必修第一册》第二章《直线和圆的方程》,本节课主要学习抛物线及其标准方程在经历了椭圆和双曲线的学习后再学习抛物线,是在学生原有认知的基础上从几何与代数两 个角度去认识抛物线.教材在抛物线的定义这个内容的安排上是:先从直观上认识抛物线,再从画法中提炼出抛物线的几何特征,由此抽象概括出抛物线的定义,最后是抛物线定义的简单应用.这样的安排不仅体现出《课程标准》中要求通过丰富的实例展开教学的理念,而且符合学生从具体到抽象的认知规律,有利于学生对概念的学习和理解.坐标法的教学贯穿了整个“圆锥曲线方程”一章,是学生应重点掌握的基本数学方法 运动变化和对立统一的思想观点在这节知识中得到了突出体现,我们必须充分利用好这部分教材进行教学
∵在△EFP中,|EF|=2c,EF上的高为点P的纵坐标,∴S△EFP=4/3c2=12,∴c=3,即P点坐标为(5,4).由两点间的距离公式|PE|=√("(" 5+3")" ^2+4^2 )=4√5,|PF|=√("(" 5"-" 3")" ^2+4^2 )=2√5,∴a=√5.又b2=c2-a2=4,故所求双曲线的方程为x^2/5-y^2/4=1.5.求适合下列条件的双曲线的标准方程.(1)两个焦点的坐标分别是(-5,0),(5,0),双曲线上的点与两焦点的距离之差的绝对值等于8;(2)以椭圆x^2/8+y^2/5=1长轴的端点为焦点,且经过点(3,√10);(3)a=b,经过点(3,-1).解:(1)由双曲线的定义知,2a=8,所以a=4,又知焦点在x轴上,且c=5,所以b2=c2-a2=25-16=9,所以双曲线的标准方程为x^2/16-y^2/9=1.(2)由题意得,双曲线的焦点在x轴上,且c=2√2.设双曲线的标准方程为x^2/a^2 -y^2/b^2 =1(a>0,b>0),则有a2+b2=c2=8,9/a^2 -10/b^2 =1,解得a2=3,b2=5.故所求双曲线的标准方程为x^2/3-y^2/5=1.(3)当焦点在x轴上时,可设双曲线方程为x2-y2=a2,将点(3,-1)代入,得32-(-1)2=a2,所以a2=b2=8.因此,所求的双曲线的标准方程为x^2/8-y^2/8=1.当焦点在y轴上时,可设双曲线方程为y2-x2=a2,将点(3,-1)代入,得(-1)2-32=a2,a2=-8,不可能,所以焦点不可能在y轴上.综上,所求双曲线的标准方程为x^2/8-y^2/8=1.
当A,C颜色相同时,先染P有4种方法,再染A,C有3种方法,然后染B有2种方法,最后染D也有2种方法.根据分步乘法计数原理知,共有4×3×2×2=48(种)方法;当A,C颜色不相同时,先染P有4种方法,再染A有3种方法,然后染C有2种方法,最后染B,D都有1种方法.根据分步乘法计数原理知,共有4×3×2×1×1=24(种)方法.综上,共有48+24=72(种)方法.故选B.答案:B5.某艺术小组有9人,每人至少会钢琴和小号中的一种乐器,其中7人会钢琴,3人会小号,从中选出会钢琴与会小号的各1人,有多少种不同的选法?解:由题意可知,在艺术小组9人中,有且仅有1人既会钢琴又会小号(把该人记为甲),只会钢琴的有6人,只会小号的有2人.把从中选出会钢琴与会小号各1人的方法分为两类.第1类,甲入选,另1人只需从其他8人中任选1人,故这类选法共8种;第2类,甲不入选,则会钢琴的只能从6个只会钢琴的人中选出,有6种不同的选法,会小号的也只能从只会小号的2人中选出,有2种不同的选法,所以这类选法共有6×2=12(种).因此共有8+12=20(种)不同的选法.
课程分析中专数学课程教学是专业建设与专业课程体系改革的一部分,应与专业课教学融为一体,立足于为专业课服务,解决实际生活中常见问题,结合中专学生的实际,强调数学的应用性,以满足学生在今后的工作岗位上的实际应用为主,这也体现了新课标中突出应用性的理念。分段函数的实际应用在本课程中的地位:(1) 函数是中专数学学习的重点和难点,函数的思想贯穿于整个中专数学之中,分段函数在科技和生活的各个领域有着十分广泛的应用。(2) 本节所探讨学习分段函数在生活生产中的实际问题上应用,培养学生分析与解决问题的能力,养成正确的数学化理性思维的同时,形成一种意识,即数学“源于生活、寓于生活、用于生活”。教材分析 教材使用的是中等职业教育课程改革国家规划教材,依照13级教学计划,函数的实际应用举例内容安排在第三章函数的最后一部分讲解。本节内容是在学生熟知函数的概念,表示方法和对函数性质有一定了解的基础上研究分段函数,同时深化学生对函数概念的理解和认识,也为接下来学习指数函数和对数函数作了良好铺垫。根据13级学生实际情况,由生活生产中的实际问题入手,求得分段函数此部分知识以学生生活常识为背景,可以引导学生分析得出。
问题1. 用一个大写的英文字母或一个阿拉伯数字给教室里的一个座位编号,总共能编出多少种不同的号码?因为英文字母共有26个,阿拉伯数字共有10个,所以总共可以编出26+10=36种不同的号码.问题2.你能说说这个问题的特征吗?上述计数过程的基本环节是:(1)确定分类标准,根据问题条件分为字母号码和数字号码两类;(2)分别计算各类号码的个数;(3)各类号码的个数相加,得出所有号码的个数.你能举出一些生活中类似的例子吗?一般地,有如下分类加法计数原理:完成一件事,有两类办法. 在第1类办法中有m种不同的方法,在第2类方法中有n种不同的方法,则完成这件事共有:N= m+n种不同的方法.二、典例解析例1.在填写高考志愿时,一名高中毕业生了解到,A,B两所大学各有一些自己感兴趣的强项专业,如表,
一、 引入课题1. 复习初中所学函数的概念,强调函数的模型化思想;2. 阅读课本引例,体会函数是描述客观事物变化规律的数学模型的思想:(1)炮弹的射高与时间的变化关系问题;(2)南极臭氧空洞面积与时间的变化关系问题;(3)“八五”计划以来我国城镇居民的恩格尔系数与时间的变化关系问题3. 引导学生应用集合与对应的语言描述各个实例中两个变量间的依赖关系;4. 根据初中所学函数的概念,判断各个实例中的两个变量间的关系是否是函数关系.
内容:分式方程的解法及应用——初三中考数学第一轮复习学习目标:1、熟练利用去分母化分式方程为整式方程2、熟练利用分式方程的解法解决含参数的分式方程的问题重点:分式方程的解法(尤其要理解“验”的重要性)难点:含参数的分式方程问题预习内容:1、观看《分式方程的解法》《含参数分式方程增根问题》《解含参分式方程》视频2、完成预习检测
一、 教学目标根据教学大纲的要求以及本节课的地位与作用,结合高一学生的认知特点确定教学目标如下:学习目标:1、复习巩固对数函数的图像及性质2、运用对数函数的性质比较两个数的大小能力目标:1、 培养学生运用图形解决问题的意识即数形结合能力2、学生运用已学知识,已有经验解决新问题的能力3、 探索出方法,有条理阐述自己观点的能力
(2) students are divided into groups according to the requirements of activity 3. Each student shares a story of personal experience or hearing-witnessing kindness, and then selects the most touching story in the group and shares it with the whole class. Before the students share the story, the teacher can instruct them to use the words and sentence patterns in the box to express. For example, the words in the box can be classified:Time order: first of all, then, after that, later, finally logical relationship :so, however, although, butTeachers can also appropriately add some transitional language to enrich students' expression:Afterwards, afterwards, at last, in the end, eventuallySpatial order: next to, far from, on the left, in front ofOtherwise, nevertheless, as a result, therefore, furthermore, in addition, as well asSummary: in a word, in short, on the whole, to sum up, in briefStep 8 Homework1. Understand the definition of "moral dilemma" and establish a correct moral view;2. Accumulate vocabulary about attitudes and emotions in listening texts and use them to express your own views;3. Complete relevant exercises in the guide plan.1、通过本节内容学习,学生能否理解理解“道德困境”的定义;2、通过本节内容学习,学生能否通过说话人所表达的内容、说话的语气、语调等来判断其态度和情绪;3、通过本节内容学习,学生能否针对具体的道德困境发表自己的看法和见解,能否掌握听力理训练中的听力策略。
2.学情分析从学生的认知基础看,学生在初中已经学习了轴对称图形和中心对称图形,并且有了一定数量的简单函数的储备。同时,刚刚学习了函数单调性,已经积累了研究函数的基本方法与初步经验。从学生的思维发展看,高一学生思维能力正在由形象经验型向抽象理论型转变,能够用假设、推理来思考和解决问题.
The joke set her crying.这个玩笑使她哭起来。Step 5 ReadingActivity 31. Students read the small text in activity 3. The teacher provides several small questions to check whether students understand the content of the text and the ideographic function of the -ing form in the text.*Where are those people?*Why did Dr Bethune come to China?*How did he help the Chinese people during the war?*What did Chairman Mao Zedong say about him?2. Ss try to rewrite some sentences using the -ing form. Then check the answers. When checking the answers, the teacher can ask different students to read the rewritten sentences and give comments.Answers:1. he became very interested in medicine, deciding to become a doctor.2. …after hearing that many people were dying in the war.3. Helping to organise hospitals, he taught doctors and nurses, and showed people how to give first aid./ He helped to organise hospitals, teaching doctors and nurses, and showing people how to give first aid.4. …praising Dr Bethune as a hero to be remembered in China.Step 6 PracticeActivity 4Students complete grammar activities 2 and 3 on page 69 of the workbook.Step 6 Homework1. Understand and master the functions and usage of the -ing form;2. Finish the other exercises in Using structures.1、通过本节内容学习,学生是否理解和掌握动词-ing形式作宾语补足语语和状语语的功能和意义;2、通过本节内容学习,学生能否正确使用动词-ing形式描述人物的行为、动作及其经历;3、通过本节内容学习,学生能否独立完成练习册和导学案中的相关练习。
本板块的活动主题是“谈论节日活动”(Talk about festival activities),主要是从贴近学生日常生活的角度来切入“节日”主题。学生会听到发生在三个国家不同节日场景下的简短对话,对话中的人们正在参与或将要亲历不同的庆祝活动。随着全球化的进程加速,国际交流日益频繁,无论是国人走出国门还是外国友人访问中国,都已成为司空见惯的事情。因此,该板块所选取的三个典型节日场景都是属于跨文化交际语境,不仅每组对话中的人物来自不同的文化背景,对话者的身份和关系也不尽相同。1. Master the new words related to holiday: the lantern, Carnival, costume, dress(sb)up, march, congratulation, congratulate, riddle, ceremony, samba, make - up, after all. 2. To understand the origin of major world festivals and the activities held to celebrate them and the significance of these activities;3. Improve listening comprehension and oral expression of the topic by listening and talking about traditional festivals around the world;4. Improve my understanding of the topic by watching pictures and videos about different traditional festivals around the world;5. Review the common assimilation phenomenon in English phonetics, can distinguish the assimilated phonemes in the natural language flow, and consciously use the assimilation skill in oral expression. Importance:1. Guide students to pay attention to the attitude of the speaker in the process of listening, and identify the relationship between the characters;2. Inspire students to use topic words to describe the festival activities based on their background knowledge. Difficulties:In the process of listening to the correct understanding of the speaker's attitude, accurately identify the relationship between the characters.
Activity 81.Grasp the main idea of the listening.Listen to the tape and answer the following questions:Who are the two speakers in the listening? What is their relationship?What is the main idea of the first part of the listening? How about the second part?2.Complete the passage.Ask the students to quickly review the summaries of the two listening materials in activity 2. Then play the recording for the second time.Ask them to complete the passage and fill in the blanks.3.Play the recording again and ask the students to use the structure diagram to comb the information structure in the listening.(While listening, take notes. Capture key information quickly and accurately.)Step 8 Talking Activity 91.Focus on the listening text.Listen to the students and listen to the tape. Let them understand the attitudes of Wu Yue and Justin in the conversation.How does Wu Yue feel about Chinese minority cultures?What does Justin think of the Miao and Dong cultures?How do you know that?2.learn functional items that express concerns.Ask students to focus on the expressions listed in activity. 3.And try to analyze the meaning they convey, including praise (Super!).Agree (Exactly!)"(You're kidding.!)Tell me more about it. Tell me more about it.For example, "Yeah Sure." "Definitely!" "Certainly!" "No kidding!" "No wonder!" and so on.4.Ask the students to have conversations in small groups, acting as Jsim and his friends.Justin shares his travels in Guizhou with friends and his thoughts;Justin's friends should give appropriate feedback, express their interest in relevant information, and ask for information when necessary.In order to enrich the dialogue, teachers can expand and supplement the introduction of Miao, dong, Lusheng and Dong Dage.After the group practice, the teacher can choose several groups of students to show, and let the rest of the students listen carefully, after listening to the best performance of the group, and give at least two reasons.
*wide range of origins(= a great number of different origins, many kinds of origins)*It featured a parade and a great feast with music, dancing, and sports. (=A parade and a great feast with music, dancing, and sports were included as important parts of the Egyptian harvest festival.)*.. some traditions may fade away and others may be established.(= Some traditions may disappear gradually, while other new traditions may come into being.)Step 6 Practice(1) Listen and follow the tape.The teacher may remind the students to pay attention to the meaning and usage of the black words in the context, so as to prepare for the completion of the blanks in activity 5 and vocabulary exercises in the exercise book.(2) Students complete the text of activity 5 by themselves.The teacher needs to remind the students to fill in the blanks with the correct form of the vocabulary they have learned in the text.Students exchange their answers with their partners, and then teachers and students check their answers.(3)Finish the Ex in Activity 5 of students’ book.Step 7 Homework1. Read the text again, in-depth understanding of the text;2. Discuss the origin of festivals, the historical changes of related customs, the influence of commercial society on festivals and the connotation and essential meaning of festivals.3. Complete relevant exercises in the guide plan.1、通过本节内容学习,学生是否理解和掌握阅读文本中的新词汇的意义与用法;2、通过本节内容学习,学生能否结合文本特点快速而准确地找到主题句;3、通过本节内容学习,学生能否理清论说文的语篇结构和文本逻辑,了解节日风俗发展与变迁,感悟节日的内涵与意义。
The price is the same as(the price was)before the war.价格与战前相同。(4)定语从句中的“关系代词+助动词be”可以省略。The ticket(that/which was)booked by his sister has been sent to him.他妹妹订的那张票已送到了他那里。Step 5 PracticeActivity 3(1) Guide students to complete the four activities in the Using Structures part of exercise book, in which activities 1 and 2 focus on ellipsis in dialogue answers, activity 3 focus on signs and headlines, two typical situations where ellipsis is used, and activity 4 focus on ellipsis in diary, an informal style.(2) Combine the examples in the above activities, ask students to summarize the omitted situations in groups, and make their own summary into a poster, and post it on the class wall after class to share with the class.(This step should give full play to the subjectivity of students, and teachers should encourage students to conclude different ellipsis phenomena according to their own understanding, they can conclude according to the different parts omitted in the sentence.)Step 6 Homework1. Understand and master the usages of ellipsis;2. Finish the other exercises in Using structures of Workbook.1、通过本节内容学习,学生是否理解和掌握省略的用法;2、通过本节内容学习,学生能否根据上下文语境或情景恢复句子中省略的成分,体会使用省略的效果;3、通过本节内容学习,学生能否独立完成练习册和导学案中的相关练习。
Activity 41. Students complete the task of activity 4, then teachers and students check the answers. 2. The teacher organized the students to work together and asked them to use the tables and mind maps sorted out before to retold the important choices in Lin Qiaozhi's life and their resultsStep 5 Language points1. The teacher asks the students to read the text carefully, find out the core words and long and difficult sentences in the text and draw lines, understand the use of vocabulary, and analyze the structure of long and difficult sentences. 2. The teacher explains and summarizes the usage of core vocabulary and asks the students to take notes. 3. The teacher analyzes and explains the long and difficult sentences that the students don't understand, so that the students can understand them better. Step 6 Homework1. Read the text again, in-depth understanding of the text; 2. Master the use of core vocabulary and understand the long and difficult sentences. 3. Complete relevant exercises in the guide plan. 1、通过本节内容学习,学生是否理解和掌握阅读文本中的新词汇的意义与用法;2、通过本节内容学习,学生能否结合文本特点总结林巧稚的人生原则和人格品质特征;3、通过本节内容学习,学生能否针对人生抉择发表自己的看法;能否全面地、客观地、理性地看待问题,进而对道德和人性有更加深入的思考和理解。