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北师大初中数学八年级上册二次根式及其化简1教案
方法总结：(1)若被开方数中含有负因数，则应先化成正因数，如(3)题．(2)将二次根式尽量化简，使被开方数(式)中不含能开得尽方的因数(因式)，即化为最简二次根式(后面学到)．探究点三：最简二次根式在二次根式8a，c9，a2＋b2，a2中，最简二次根式共有()A．1个 B．2个C．3个 D．4个解析：8a中有因数4；c9中有分母9；a3中有因式a2.故最简二次根式只有a2＋b2.故选A.方法总结：只需检验被开方数是否还有分母，是否还有能开得尽方的因数或因式．三、板书设计二次根式定义形如a（a≥0）的式子有意义的条件：a≥0性质：（a）2＝a（a≥0），a2＝a（a≥0）最简二次根式本节经历从具体实例到一般规律的探究过程，运用类比的方法，得出实数运算律和运算法则，使学生清楚新旧知识的区别和联系，加深学生对运算法则的理解，能否根据问题的特点，选择合理、简便的算法，能否确认结果的合理性等等．
北师大初中数学八年级上册二次根式及其化简2教案
属于此类问题一般有以下三种情况①具体数字，此时化简的条件已暗中给定，②恒为非负值或根据题中的隐含条件，如（1）小题。③给出明确的条件，如（2）小题。第二类，需讨论后再化简。当题目中给定的条件不能判定绝对值符号内代数式值的符号时，则需讨论后化简，如（4）小题。例3．已知a+b=-6,ab=5，求 的值。解：∵ab=5>0,∴a,b同号，又∵a+b=-6<0,∴a<0,b<0∴ .说明：此题中的隐含条件a<0,b<0不能忽视。否则会出现错误。例4．化简： 解：原式=|x-6|-|1+2x|+|x+5|令x-6=0，得x=6，令1+2x=0，得 ，令x+5=0，得x=-5.这样x=6, ,x=-5，把数轴分成四段（四个区间）在这五段里分别讨论如下：当x≥6时，原式=(x-6)-(1+2x)+(x+5)=-2.当 时，原式=-(x-6)-(1+2x)+(x+5)=-2x+10.当 时，原式=-(x-6)-[-(1+2x)]+(x+5)=2x+12.当x<-5时，原式=-(x-6)+(1+2x)-(x+5)=2.说明：利用公式 ，如果绝对值符号里面的代数式的值的符号无法决定，则需要讨论。方法是：令每一个绝对值内的代数式为零，求出对应的“零点”，再用这些“零点”把数轴分成若干个区间，再在每个区间内进行化简。
北师大初中数学八年级上册轴对称与坐标变化2教案
8.一束光线从点Ａ（３，３）出发，经过ｙ轴上点Ｃ反射后经过点Ｂ（１，0）则光线从Ａ点到Ｂ点经过的路线长是（ ）A．4 B．5 C．6 D．7第四环节课堂小结1、关于y轴对称的两个图形上点的坐标特征：(x , y)——(- x , y)2、关于x轴对称的两个图形上点的坐标特征：(x , y)——(x , - y)3、关于原点对称的两个图形上点的坐标特征：(x , y)——(- x , -y)第五环节布置作业习题3.5 1，2，3四、 教学反思通过“坐标与轴对称”，经历图形坐标变化与图形的轴对称之间的关系的探索过程， 掌握空间与图形的基础知识和基本技能，丰富对现实空间及图形的认识，建立初步的空间观念，发展形象思维，激发学生对数学学习的好奇心与求知欲，学生能积极参与数学学习活动；积极交流合作，体验数学活动充满着探索与创造。教学中务必给学生创造自主学习与合作交流的机会，留给学生充足的动手机会和思考空间，教师不要急于下结论。事先一定要准备好坐标纸等，提高课堂效率。
北师大初中数学八年级上册轴对称与坐标变化1教案
解析：从各点的位置可以发现A1(1，0)，A2(1，1)，A3(－1，1)，A4(－1，－1)，A5(2，－1)，A6(2，2)，A7(－2，2)，A8(－2，－2)，A9(3，－2)，A10(3，3)，A11(－3，3)，A12(－3，－3)，….仔细观察每四个点的横、纵坐标，发现存在着一定规律性．因为2015＝503×4＋3，所以点A2015在第二象限，纵坐标和横坐标互为相反数，所以A2015的坐标为(－504，504)．故填(－504，504)．方法总结：解决此类题常用的方法是通过对几种特殊情况的研究，归纳总结出一般规律，再根据一般规律探究特殊情况．三、板书设计轴对称与坐标变化关于坐标轴对称作图——轴对称变换通过本课时的学习，学生经历图形坐标变化与图形的轴对称之间的关系的探索过程，掌握空间与图形的基础知识和基本作图技能，丰富对现实空间及图形的认识，建立初步的空间观念，发展形象思维，激发数学学习的好奇心与求知欲．教学过程中学生能积极参与数学学习活动，积极交流合作，体验数学活动的乐趣．
北师大初中数学八年级上册单个一次函数图象的应用2教案
（1）用简洁明快的语言概括大意，不能超过200字；（2）图表中能确定的数值，在故事叙述中不得少于3个，且要分别涉及时间、路和速度这三个量．意图：旨在检测学生的识图能力，可根据学生情况和上课情况适当调整。说明：练习注意了问题的梯度，由浅入深，一步步引导学生从不同的图象中获取信息，对同学的回答，教师给予点评，对回答问题暂时有困难的同学，教师应帮助他们树立信心。第四环节：课时小结内容：本节课我们学习了一次函数图象的应用，在运用一次函数解决实际问题时，可以直接从函数图象上获取信息解决问题，当然也可以设法得出各自对应的函数关系式，然后借助关系式完全通过计算解决问题。通过列出关系式解决问题时，一般首先判断关系式的特征，如两个变量之间是不是一次函数关系？当确定是一次函数关系时，可求出函数解析式，并运用一次函数的图象和性质进一步求得我们所需要的结果．
北师大初中数学八年级上册单个一次函数图象的应用1教案
方法总结：要认真观察图象，结合题意，弄清各点所表示的意义．探究点二：一次函数与一元一次方程一次函数y＝kx＋b(k，b为常数，且k≠0)的图象如图所示，根据图象信息可求得关于x的方程kx＋b＝0的解为()A．x＝－1B．x＝2C．x＝0D．x＝3解析：首先由函数经过点(0，1)可得b＝1，再将点(2，3)代入y＝kx＋1，可求出k的值为1，从而可得出一次函数的表达式为y＝x＋1，再求出方程x＋1＝0的解为x＝－1，故选A.方法总结：此题主要考查了一次函数与一元一次方程的关系，关键是正确利用待定系数法求出一次函数的关系式．三、板书设计一次函数的应用单个一次函数图象的应用一次函数与一元一次方程的关系探究的过程由浅入深，并利用了丰富的实际情景，增加了学生的学习兴趣．教学中要注意层层递进，逐步让学生掌握求一次函数与一元一次方程的关系．教学中还应注意尊重学生的个体差异，使每个学生都学有所获．
北师大初中数学八年级上册两个一次函数图象的应用1教案
解：∵y＝23x＋a与y＝－12x＋b的图象都过点A(－4，0)，∴32×(－4)＋a＝0，－12×(－4)＋b＝0.∴a＝6，b＝－2.∴两个一次函数分别是y＝32x＋6和y＝－12x－2.y＝32x＋6与y轴交于点B，则y＝32×0＋6＝6，∴B(0，6)；y＝－12x－2与y轴交于点C，则y＝－2，∴C(0，－2)．如图所示，S△ABC＝12BC·AO＝12×4×(6＋2)＝16.方法总结：解此类题要先求得顶点的坐标，即两个一次函数的交点和它们分别与x轴、y轴交点的坐标．三、板书设计两个一次函数的应用实际生活中的问题几何问题进一步训练学生的识图能力，能通过函数图象获取信息，解决简单的实际问题，在函数图象信息获取过程中，进一步培养学生的数形结合意识，发展形象思维．在解决实际问题的过程中，进一步发展学生的分析问题、解决问题的能力和数学应用意识．
北师大初中数学八年级上册两个一次函数图象的应用2教案
学习目标1.掌握两个一次函数图像的应用；（重点）2.能利用函数图象解决实际问题。（难点）教学过程一、情景导入在一次蜡烛燃烧实验中，甲、乙两根蜡烛燃烧时剩余部分的高度y（厘米）与燃烧时间x（小时）之间的关系如图所示．请你根据图象所提供的信息回答下列问题：甲、乙两根蜡烛燃烧前的高度分别是 厘米、 厘米，从点燃到燃尽所用的时间分别是 小时、 小时．你会解答上面的问题吗？学完本解知识，相信你能很快得出答案。二、 合作探究探究点一：两个一次函数的应用（2015?日照模拟）自来水公司有甲、乙两个蓄水池，现将甲池的中水匀速注入乙池，甲、乙两个蓄水池中水的深度y（米）与注水时间x（时）之间的函数图象如下所示，结合图象回答下列问题．（1）分别求出甲、乙两个蓄水池中水的深度y与注水时间x之间的函数表达式；（2）求注入多长时间甲、乙两个蓄水池水的深度相同；（3）求注入多长时间甲、乙两个蓄水的池蓄水量相同；
XX-XX学年第1学期第14周国旗下讲话稿：“八礼四仪”教育
老师们，同学们，大家上午好!今天我国旗下讲话的主题是：学“八礼四仪”，让文明传承。全国都在开展文明礼仪养成教育，强调要突出抓好未成年人的“八礼四仪”，具体包括仪表之礼、餐饮之礼、言谈之礼、待人之礼、行走之礼、观赏之礼、游览之礼、仪式之礼这八个方面的礼仪教育。四仪是指7岁入学仪式;10岁成长仪式;14岁青春仪式;18岁成人仪式。这套“八礼四仪”融入了“爱、善、诚、勤、俭、美”六种理念和价值取向，注重从生活细节入手，未成年人易懂易学易做。“八礼四仪”是传承文明的需要。古老的中华民族自古以来就享有“礼仪之邦”的美称。在五千年悠久的历史长河中，不但创造了灿烂的文化，而且形成了古老民族的传统美德，很多优良的、传统的礼仪规范，直至今天仍然有很强大的生命力，它是中华民族的宝贵的精神财富。
部编版语文八年级下册《阿西莫夫短文两篇》教案
第一部分（第1~4段），提出关于6500万年前恐龙灭绝的问题，目前存在的两种对立的理论，即“撞击说”和“火山说”。第2和第3自然段先后举了两个例子提出了关于“撞击说”和“火山说”这两种观点。第二部分（第5段至全文完），通过对“被压扁的沙子”的反思，证明外星撞击导致恐龙灭绝，支持“撞击说”。这部分又分四层。第一层（第5、6段），说明关于恐龙灭绝的原因不仅仅是一个学术问题，我们以后也许还会遇到这种情况，因此，科学家们一直都在努力寻找证据来验证这两种理论。第二层（第7~10段），说明1961年一位苏联科学家发现了“斯石英”，并且介绍了它的性质，为下文佐证“撞击说”奠定了基础。第三层（第11~13段），说明斯石英不仅可以在实验室制造，而且它在自然界中是可以存在的，不过它们只出现在沙子被强烈挤压的地方。由此推断撞击是可以产生斯石英的。事实也证明，火山喷发是不会产生斯石英的，从而进一步佐证了“撞击说”。
人教版新目标初中英语八年级上册How do you make a banana milk shake教案2篇
1. First, ... then, ... next, ... finally, ...首先，……然后，……接着，……最后，……这是英语中表达做某事的步骤的一种说法。如果步骤较多，还可以说：first-next-after that-later on-finally/at last通常你会听到说英语国家的人在说 first, next, then, finally 和后面的内容时，他们会做一些停顿。这样就能提前告诉听者接下来讲的是一系列的步骤。这一点在朗读和听力中应特别注意。2. how many, how much均为疑问词，同是“多少”，但用法不同。请看：how many修饰可数名词复数，how much修饰不可数名词。但在用法上，同学们常犯如下错误：1) [误] How many are there bananas on the table?[正] How many bananas are there on the table?[析] how many, how much 中的many，much是形容词，常修饰名词作定语，故后面跟名词。2) [误]How much tea are there on the table?[正]How much tea is there on the table?[析] how much修饰不可数名词时，谓语动词用单数。how many与how much的区别可简记为：前how many：问“多少”，复数名词后面跑；how much问“多少”，不可数名词单数好。前者答语用基数词，后者答语用数量关系。
人教版新目标初中英语八年级上册Could you please clean your room教案3篇
一、 教学内容Section A 1a----1c二、 教学目标1.学习词汇do the dishes, make the bed, take out the trash, fold the clothes, do the laundry, sweep the floor, clean the living room.2.句型 Could you please clean your room? Yes, sure.三、 教学准备 学生预习本单元所有的词汇多媒体课件 活动表 奖品四、 教学过程Pre-task1. Warming upEnjoy ourselves. Watch cartoon Cinderella. 看动画片段《灰姑娘》导如入本课话题和新词汇“chores”美丽善良的鬼姑娘因继母的嫉妒，每天得做所有的家务。片段的主题使学生联想到本课的话题。2. learn new words and phrasesLook! What is she / he dong? 看图学习动词词组do chores, do the dishes, make the bed, take out the trash, fold the clothes, do the laundry, clean the living room.3. Guessing game.What is she doing ? 4. Pair work. 1a, Do you do these things at home? Write “Y” for “yes” and “N” for “no”.5. Listening . 1b , Peter’s chores or Mom’s chores?理解目标语Could you please clean your room? Yes, sure.Write “M” for Mom’s chores, “P” for Peter’s chores in the chart.6. PairworkLook at the picture,Ask your partner to do the chores that you see. 7. Interview Who is the most able at home? 1) What chores do you do at home? How often do you do the chores? Work in four, interview each of the students in the group, fill in the chart.
人教版新目标初中英语八年级上册I’m going to be a basketball player教案3篇
教学目标1.知识目标：（1）学习What are you going to be when you grow up?/How are you going to do that?句式。（2）学会用英语描述有关职业的表达法。2.能力目标：（1）能够谈论为实现理想所做出的打算和安排。（2）能够谈论未来自己与他人理想的职业及原因。（3）能用英语描述课余时间的活动安排，最终具备表达综合信息的能力。3.情感目标：新学期到来之际，让他们在学习、体育、饮食、特长、读书等方面制定计划，教育学生合理安排自己的课外生活，思考自己的理想职业及适合自己的职业。教学重点、难点本单元的重点为“be going to”表将来,want to be, what,where, when,how引导的特殊疑问句。难点是语言目标的实现。教材分析本单元以I am going to be a basketball player为话题，共设计了三部分的内容：一、Section A该部分有4个模块。第一模块围绕Do you think these jobs are interesting?这一话题展开思维（1a）、听力（1b）、口语（1c）训练；
人教版新目标初中英语八年级上册I’m more outgoing than my sister教案2篇
1 交通工具的比较此活动为小组活动。学生通过讨论找出到达某一城市可乘坐的各种交通工具，并选择最佳出行方式。Teacher:We’re going to Shanghai. How many ways can we use to get there? Yes, there are four ways: by bus, by plane, by train, by ship. Please discuss how you are going to get there.操作建议：（1）学生以小组为单位展开活动，谈论本组所选择的交通工具。（2）各组选代表向全班汇报，阐述本组所选择的交通工具的利和弊。完成任务所需要的语言结构：We can go there by ship. It’s more comfortable and cheaper than any other transportation.We can go there by bus. It’s cheaper but it takes longer time.2 哪个城市更合适？此活动具有挑战性。假设中国要举行2014年世界杯足球赛，分别从历史，人文，天气等方面对各城市（北京，大连，上海，昆明）进行比较，选择最佳举办城市。T: Imagine China is holding the 2014 FIFA World Cup. Which city do you think is the best for the World Cup, Beijing, Dalian, Shanghai or Kunming? Let’s work in groups. If you choose Beijing, please join the Team Red. If you chose Dalian, please join the Team White. If you choose Shanghai, please join the Team Blue. If you choose Kunming, please join the Team Green. Please show us its advantages. Then let’s see which team will win.
人教版新目标初中英语八年级下册If you go to the party, you’ll have a great time教案2篇
区分宾语从句、定于从句和状语从句宾语从句和状语从句，都叫做主从复合句。宾语从句主要是中考必考的，是初中阶段必掌握的从句，宾语从句主要是掌握三要素，所谓宾语从句，就是宾语在主从复合句当中充当宾语的一个句子，叫做宾语从句。主句的谓语动词是及物动词，后面如果是词或者是短语的话，是简单句，如果是句子的话，肯定是宾语从句。I know that he good at English.就是宾语从句，三要素，一要素是要注意连词，连词一共学了三类连词，一类连词是that口语当中可以省略，就像刚才说的那一句，I hear he is good at English.还有疑问代词、疑问副词，how where when，疑问代词、疑问副词。还有一类连词weather是否的意思，不是状语从句当中的如果，这一定要和如果区分开，这是是否。I don't know if he interested at English。宾语从句要注意if是连词。第二要素是语序，要用陈述举语序。比如说你家有几口人，我们都说How many people are there in you family?但是这是简单句，一旦说成宾语从句，你可以告诉我你家有几口人吗？Could you tell me how many people there are in you family ?
人教版新目标初中英语八年级下册How long have you been collecting shells教案2篇
Step Ⅱ Show the new words on the screen and teach the new words. Read the new words to students and ask them to repeat.Step Ⅲ 3aThis activity introduces new vocabulary and provides reading practice using the target language.In this activity first look at the four pictures.T: What can you see in the pictures?Ss: Four snow globes.T: Right. There are four snow globes in the pictures. And what are they?Ss: They are a monster, two polar bears, two penguins and a birthday cake.Write these words on the blackboard: snow globe; monster; polar bear; penguin and birthday cake. Read them to the class and ask students to repeat each one. Make sure students understand each word.Use a computer to show the E-mail message on the screen and read the message to students.Get students to read the e-mail on their own, and then draw lines connecting each snow globe and its description.Correct the answers.AnswersA line should connect each snow globe picture with the words that describe it in the letter.Step Ⅳ 3bThis activity provides writing practice using the target language.First review Activity 2a on Page 47.Then ask students to complete the message according to Activity 2a.Some partial sentences are given to students. Write about one person's collection.When students work, walk around the room checking the progress and offering help as needed.When they finish, ask some students to read their messages to the class.
人教版新目标初中英语八年级上册Can you come to my party教案3篇
Step 3 (3b)First, tell the students when we talk about our future plans, we often use: I’m+verb+ing When we talk about what we must do, we use have to. Ask the students to fill in the blanks in 3b. The answers are: shopping, go to see, a test, I’m going, my family. Step 4 (3c)Let the students write an e-mail message to a friend. Say why you can’t visit next. Before the exercise, ask the students to give some possible answers and write them on the blackboard. So the students will feel easy to finish the writing exercise. After they finish it, Let them to correct it in groups first. Each group chooses theirs best one to read in front of the whole class. Step 5 ( planning a party )First read the conversation in the box together. Then ask the students to turn to page 88.Write down everything you have to do next week. Write in all the things you have to do . Ask the students to look at the list. Ask them “What day are you free?” This is when you can have your party. Step 6 (Self check 1 )Let the students to fill in the blanks with the words given. Change the forms of the words if possible. Then make their own sentences. The answers are: visit, playing, have to, study, comeStep 7 (Self check 2)Imagine you are Marie. Read the information and look at your schedule. Write replies to the invitation.
人教版新目标初中英语八年级上册How was your school trip教案2篇
“Go for it!” is based on “Task-Based Language Teaching”. It adheres to “The authenticity principle”, “The form-function principle”, “The task dependency principle” and “The principle of learning by doing”. These principles all accord with the demands of curriculum focus.In and of Grade Seven (II), “Go for it!”, students have learned “The Simple Past Tense”. And it appears again in of Grade Eight (I). teaches students more about how to talk about events in the past. In addition, it gives affirmative and negative statements in the past tense, such as the sentence patterns “Did you see …?” “Were there …?” “Did you go …?” As the first part of Unit 8, Section A opens with a picture presenting the last school trip in the aquarium and continues with several step-by-step practice activities, which are all good for students to master “The Simple Past Tense”. Doing well in Section A will help students integrate the new target language with that in Section B. Thus, they can describe the events in the past freely and foster their own ability of reflecting and practicing. II. Teaching ObjectivesTeaching objective is the beginning and aim of teaching activities. According to the overall goal of the English elementary course--- improve students' synthetic ability of language application, which should be based on the development of students’ “Language knowledge”, “Language skills”, “Character building”, “Learning strategies” and “Cross-cultural awareness”. The teaching objectives are described as follows(I). Knowledge objectivesi. Master the simple past tense of regular and irregular verbsii. Recite the new words and expressions about the last school trip in the aquarium, including their pronunciation and intonation
人教版新目标初中英语八年级上册How do you get to school教案2篇
Step Ⅶ Role play ( Work on 1b)1. First ask two students to read the dialogue to the class.Sa: How do you get to school?Sb: Well, I ride my bike to the subway station. Then I take the subway.2. Now work with a partner.Suppose you use two kinds of transportation to get to school \Hangzhou\Beijing... (bus, train, subway, walking, bike, etc.) Tell how you get there. You may use the phrases in 1a.3. Then ask different pairs of students to present their conversations to the class.Step ⅧListening1. Work on 2a(1) First ask students to read the list of information that Thomas wants to know.…where Nina lives.…how far from school she lives.…how long it takes to get to school.…how she gets to school.…what she thinks of the transportation.(2) Tell students what transportation and bus stop mean.bus stop 汽车站 transportation n. 运送；运输Then tell students we'll hear a recording. Please put a checkmark in front of each thing that Thomas wants to know.(3) Now play the recording for students.( Have students pay attention to the sample answer.) (4) Then correct the answers.
人教版新目标初中英语八年级上册What are you doing for vacation教案2篇
Teaching goals : 1. Words & phrases: babysit ,get back , fishing , rent , think about , decide(on) , tourist etc. 2. How to talk about future plans . 3. 现在进行时表示将来计划或行动. 4. 特殊疑问句（where , when , how long引导） Important and difficult points : Drills :What are you doing for vacation ? I’m watching TV . When are you going ? I’m going … . How long are you staying ? We’re staying for five days . Teaching aids : cards and a tape ,a large wall calendar . Period 1 Teaching procedures : Step 1Leading in1. Free talk . 2. Put up the wall calendar . T: I’m staying home on Saturday (pointing to next Saturday ).Ss repeat . Ss: I’m staying home on Saturday . T: OK. Today we’ll learn how to talk about future plans. Step 2Pre-task SB Page 13 , 1a . 1. Look at the picture carefully and tell what you see in the picture . 2. Write the activities from the pictures in the box and add some more . 3. Practice reading . Step 3While-task1. Using the activities we write in 1a to make conversations .For example :What are you doing for vacation ? I’m visiting my uncle . 2. Pairwork .Practice in pairs . 3. 用第三人称练习对话.