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北师大初中数学九年级上册用配方法求解简单的一元二次方程1教案
探究点二：用配方法解二次项系数为1的一元二次方程用配方法解方程：x2＋2x－1＝0.解析：方程左边不是一个完全平方式，需将左边配方．解：移项，得x2＋2x＝1.配方，得x2＋2x＋(22)2＝1＋(22)2，即(x＋1)2＝2.开平方，得x＋1＝±2.解得x1＝2－1，x2＝－2－1.方法总结：用配方法解一元二次方程时，应按照步骤严格进行，以免出错．配方添加时，记住方程左右两边同时加上一次项系数一半的平方．三、板书设计用配方法解简单的一元二次方程：1．直接开平方法：形如(x＋m)2＝n(n≥0)用直接开平方法解．2．用配方法解一元二次方程的基本思路是将方程转化为(x＋m)2＝n(n≥0)的形式，再用直接开平方法，便可求出它的根．3．用配方法解二次项系数为1的一元二次方程的一般步骤：(1)移项，把方程的常数项移到方程的右边，使方程的左边只含二次项和一次项；(2)配方，方程两边都加上一次项系数一半的平方，把原方程化为(x＋m)2＝n(n≥0)的形式；(3)用直接开平方法求出它的解．
北师大初中数学九年级上册用因式分解法求解一元二次方程1教案
探究点二：选用适当的方法解一元二次方程用适当的方法解方程：(1)3x(x＋5)＝5(x＋5)；(2)3x2＝4x＋1；(3)5x2＝4x－1.解：(1)原方程可变形为3x(x＋5)－5(x＋5)＝0，即(x＋5)(3x－5)＝0，∴x＋5＝0或3x－5＝0，∴x1＝－5，x2＝53；(2)将方程化为一般形式，得3x2－4x－1＝0.这里a＝3，b＝－4，c＝－1，∴b2－4ac＝(－4)2－4×3×(－1)＝28＞0，∴x＝4±282×3＝4±276＝2±73，∴x1＝2＋73，x2＝2－73；(3)将方程化为一般形式，得5x2－4x＋1＝0.这里a＝5，b＝－4，c＝1，∴b2－4ac＝(－4)2－4×5×1＝－4＜0，∴原方程没有实数根．方法总结：解一元二次方程时，若没有具体的要求，应尽量选择最简便的方法去解，能用因式分解法或直接开平方法的选用因式分解法或直接开平方法；若不能用上述方法，可用公式法求解．在用公式法时，要先计算b2－4ac的值，若b2－4ac＜0，则判断原方程没有实数根．没有特殊要求时，一般不用配方法．
北师大初中八年级数学下册一元一次不等式与一次函数的关系教案
解析：先利用正比例函数解析式确定A点坐标，然后观察函数图象得到，当1＜x＜2时，直线y＝2x都在直线y＝kx＋b的上方，于是可得到不等式0＜kx＋b＜2x的解集．把A(x，2)代入y＝2x得2x＝2，解得x＝1，则A点坐标为(1，2)，∴当x＞1时，2x＞kx＋b.∵函数y＝kx＋b(k≠0)的图象经过点B(2，0)，即不等式0＜kx＋b＜2x的解集为1＜x＜2.故选C.方法总结：本题考查了一次函数与一元一次不等式的关系：从函数的角度看，就是寻求使一次函数y＝ax＋b的值大于(或小于)0的自变量x的取值范围；从函数图象的角度看，就是确定直线y＝kx＋b在y轴上(或下)方部分所有的点的横坐标所构成的集合．三、板书设计1．通过函数图象确定一元一次不等式的解集2．一元一次不等式与一次函数的关系本课时主要是掌握运用一次函数的图象解一元一次不等式，在教学过程中采用讲练结合的方法，让学生充分参与到教学活动中，主动、自主的学习.
北师大初中数学八年级上册应用二元一次方程组——里程碑上的数1教案
A、B两码头相距140km，一艘轮船在其间航行，顺水航行用了7h，逆水航行用了10h，求这艘轮船在静水中的速度和水流速度．解析：设这艘轮船在静水中的速度为xkm/h，水流速度为ykm/h，列表如下，路程 速度 时间顺流 140km (x＋y)km/h 7h逆流 140km (x－y)km/h 10h解：设这艘轮船在静水中的速度为xkm/h，水流速度为ykm/h.由题意，得7（x＋y）＝140，10（x－y）＝140.解得x＝17，y＝3.答：这艘轮船在静水中的速度为17km/h，水流速度为3km/h.方法总结：本题关键是找到各速度之间的关系，顺速＝静速＋水速，逆速＝静速－水速；再结合公式“路程＝速度×时间”列方程组．三、板书设计“里程碑上的数”问题数字问题行程问题数学思想方法是数学学习的灵魂．教学中注意关注蕴含其中的数学思想方法(如化归方法)，介绍化归思想及其运用，既可提高学生的学习兴趣，开阔视野，同时也提高学生对数学思想的认识，提升解题能力．
北师大初中八年级数学下册一元一次不等式与一次函数的综合应用教案
解析：(1)根据题设条件，求出等量关系，列一元一次方程即可求解；(2)根据题设中的不等关系列出相应的不等式，通过求解不等式确定最值，求最值时要注意自变量的取值范围．解：设购进A种树苗x棵，则购进B种树苗(17－x)棵，(1)根据题意得80x＋60(17－x)＝1220，解得x＝10，所以17－x＝17－10＝7，答：购进A种树苗10棵，B种树苗7棵；(2)由题意得17－x172，所需费用为80x＋60(17－x)＝20x＋1020(元)，费用最省需x取最小整数9，此时17－x＝17－9＝8，此时所需费用为20×9＋1020＝1200(元)．答：购买9棵A种树苗，8棵B种树苗的费用最省，此方案所需费用1200元．三、板书设计一元一次不等式与一次函数关系的实际应用分类讨论思想、数形结合思想本课时结合生活中的实例组织学生进行探索，在探索的过程中渗透分类讨论的思想方法，培养学生分析、解决问题的能力，从新课到练习都充分调动了学生的思考能力，为后面的学习打下基础.
北师大初中数学九年级上册利用一元二次方程解决面积问题1教案
∴此方程无解．∴两个正方形的面积之和不可能等于12cm2.方法总结：对于生活中的应用题，首先要全面理解题意，然后根据实际问题的要求，确定用哪些数学知识和方法解决，如本题用方程思想和一元二次方程的根的判定方法来解决．三、板书设计列一元二次方程解应用题的一般步骤可以归结为“审，设，列，解，检，答”六个步骤：(1)审：审题要弄清已知量和未知量，问题中的等量关系；(2)设：设未知数，有直接和间接两种设法，因题而异；(3)列：列方程，一般先找出能够表达应用题全部含义的一个相等关系，列代数式表示相等关系中的各个量，即可得到方程；(4)解：求出所列方程的解；(5)检：检验方程的解是否正确，是否保证实际问题有意义；(6)答：根据题意，选择合理的答案．经历列方程解决实际问题的过程，体会一元二次方程是刻画现实世界中数量关系的一个有效数学模型．通过学生创设解决问题的方案，增强学生的数学应用意识和能力.
部编版语文七年级下册《外国诗两首（假如生活欺骗了你 未选择的路）》教案
写作背景这首诗写于普希金被沙皇流放的日子里，是以赠诗的形式写在他的邻居奥希泊娃的女儿叶甫勃拉克西亚·尼古拉耶夫娜·伏里夫纪念册上的。那里俄国革命正如火如荼，诗人却被迫与世隔绝。在这样的处境下，诗人却没有丧失希望与斗志，他热爱生活，执着地追求理想，相信光明必来，正义必胜。（三）、问题探究1、“假如生活欺骗了你”指的是什么？指在生活中因遭遇艰难困苦甚至不幸而身处逆境。作者写这首诗时正被流放，是自己真实生活的写照。2、诗人在诗中阐明了怎样的人生态度？请结合你感受最深的诗句说说你曾有过的体验。诗中阐明了这样一种积极乐观的人生态度：当生活欺骗了你时，不要悲伤，不要心急；在苦恼的时候要善于忍耐，一切都会过去，我们一定要永葆积极乐观的心态；生活中不可能没有痛苦与悲伤，欢乐不会永远被忧伤所掩盖，快乐的日子终会到来。
小学讲诚信懂礼仪公民教育实践活动教学教案
二、教学过程：1、活动一：讲故事，学诚信。1）师：春秋战国时期，商鞅下令在都城南门外立一根三丈长的木头，并许下诺言：谁能把这根木头搬到北门，赏金十两。有人将木头扛到了北门，商鞅立即赏了他五十金。商鞅这一举动，在百姓心中树立起了威信。而商鞅接下来的变法就很快在秦国推广开了，新法使秦国渐渐强盛，最终统一了中国。
大班语言教案：城市老鼠和乡村老鼠 大班语言综合活动
一、活动目标1、欣赏图片，感受城市、乡村各具特色的美景和生活。2、在辩论活动中了解城市和农村的不同生活方式，懂得适合自己的才是最好的。二、 活动准备：1、事先安排幼儿参观城市或者乡村，布置主题墙面的城市和乡村的图片。2、情景童话剧表演，布置场地。3、动画制作。4、城市和乡村的图片若干张
大班体育教案：民间体育游戏活动设计—跳竹竿
二、活动目标：1、利用纸棒进行活动，学习跳竹竿游戏，发展弹跳能力。2、体验与同伴合作游戏带来的快乐。3、愿意积极想办法解决活动中遇到的困难。三、活动准备：经验准备：幼儿观看过录像物质准备：人手一根纸棒（长度为1米）。录音机，磁带。四、活动过程：1、开始部分：幼儿随音乐利用纸棒进行队列练习。导语：今天天气真不错，我们骑着马出去玩玩吧！（幼儿随音乐的变化“骑马”变双圆----大圆----小圆---- “坐马车” ）反思：活动开始部分设计了随音乐利用纸棒进行队列练习在这一环节中由两队“骑马”变双圆----变小圆----合作组合“坐马车”体现了动静交替的原则，让幼儿初步尝试了与同伴合作的快乐，同时也为下一个环节奠定了基础。2、基本部分：（1）利用纸棒进行“一棒多玩”导语：纸棒可以和我们玩坐马车的游戏，还可以和我们玩什么游戏呢？我们一起来试试，可以自己玩，也可以和小伙伴一起玩。（幼儿四散游戏）队形：两路纵队（见附图）（2）学习“跳竹竿”游戏A、讲解游戏玩法导语：刚才小朋友用纸棒玩了许多游戏，今天老师要和大家用纸棒玩一个新游戏——跳竹竿，这个游戏可以三个或四个小朋友一起玩，其中两个小朋友手拿竹竿面对面跪下，用竹竿同时分合敲击，另一个小朋友在中间看准竹竿的分合跳进或跳出。大家可以自己选择小伙伴一起试一试。队形：梯形队（见附图）（3）幼儿自由组合尝试玩“跳竹竿”游戏队形：四散（4）对幼儿在游戏过程中出现的情况及时进行指导（合作、交往方面）导语：你刚才和谁一起玩的？你们是怎么跳竹竿的？队形：梯形队（见附图）（5）鼓励幼儿创造性地玩“跳竹竿”游戏，师生共同参与。
大班体育教案：快乐的户外区域体育——探险寻宝
2、增强规则意识：根据指示箭头有序活动，不随便插队。3、敢于挑战困难，勇敢坚强。4、感受运动的快乐，愉悦身心。（一）平衡区——过鳄鱼桥活动目标：1、在梯子、轮胎、摇板等组合器械上行走，提高平衡能力。2、克服困难，勇敢前进。
小班艺术教案“蜘蛛先生造房子”（放射线和小短线来造型
2、 在故事和儿歌的帮助下，理解蜘蛛网的基本构造。 3、 体验帮助他人的快乐。 活动准备： 课件（蜘蛛、蜘蛛先生造房子的幻灯片、蜘蛛网）、幼儿绘画纸（上有蜘蛛），蜡笔 活动过程： 一、故事导入，引发兴趣。 1、 课件出示蜘蛛，让幼儿观察认识蜘蛛。 2、 结合课件，教师讲述故事《蜘蛛先生造房子》。 问：蜘蛛先生在找什么？ 蜘蛛先生是用什么造房子的？ 蜘蛛先生的房子是怎样的？ 3、出示相应的蜘蛛网让幼儿观察蜘蛛网的构造。
新人教版高中英语选修2Unit 2 Learning about Language教学设计
The activity theme of this section is to design various activities around the key words in the first text. Therefore, the activities require students to pay attention to the spelling of words. On the other hand, let students grasp the meaning of words more accurately through sentences and short texts. This kind of teaching design also helps to improve the ability of using English thinking.1. Cultivating students' ability to use word formation to induce and memorize vocabulary, and the ability to use lexical chunks to express meaning.2. Guide the students to think independently and use the correct form of words to complete sentences3. Cultivate students' habit of using lexical chunks to express language completely, guide students to draw words in sentences quickly, pay attention to word collocation, so as to accumulate more authentic expressions4. Instruct students to create sentences with the chunks.1. Enable students to use the language points in the real situation or specific contexts flexibly and appropriately.2. Guiding the Ss to use unit topic words and the sentence patterns in a richer context.Step1: Think of a word that best fits each definition.1. to remember sth2.to accept, admit, or recognize sth or the truth/existence of sth3. the process of changing sth or yourself to suit a new situation4 .to make sb feel less worried or unhappy5. a strong desire to achieve sth
新人教版高中英语选修2Unit 2 Using langauge-Listening教学设计
? B: Absolutely! Getting involved with Chinese cultural activities there definitely helped a lot. I got to practice my Chinese on a daily basis, and I could learn how native Chinese speakers spoke.? A: What do you feel is your biggest achievement?? B: Learning Chinese characters! I have learnt about 1,500 so far. When I first started, I didn't think it was even going to be possible to learn so many, but now I find that I can read signs, menus, and even some easy newspaper articles.? A: What are you most keen on?? B: I've really become keen on learning more about the Chinese culture, in particular Chinese calligraphy. As I have learnt Chinese characters, I have developed a great appreciation for their meaning. I want to explore Chinese characters by learning how to write them in a more beautiful way. ? A: Finally, what do you want to say to anyone interested in learning Chinese?? I have really become keen on learning more about the Chinese culture, in particular Chinese Calligraphy. As I have learnt Chinese character, I have developed a great appreciation for their meaning. I want to explore Chinese characters by learning how to write them in a more beautiful way.? A: Finally, what do you want to say to anyone interested in learning Chinese?? B: I'd say, give it a shot! While some aspects may be difficult, it is quite rewarding and you will be happy that you tried.? A: Thanks for your time. ? B:You're welcome.
新人教版高中英语选修2Unit 2 Reading and thinking教学设计
Her tutor told her to acknowledge __________ other people had said if she cited their ideas, and advised her _______（read） lots of information in order to form __________wise opinion of her own.Now halfway __________ her exchange year, Xie Lei felt much more at home in the UK. She said __________ (engage) in British culture had helped and that she had been__________ (involve) in social activities. She also said while learning about business, she was acting as a cultural messenger __________（build） a bridge between the two countries. keys:Xie Lei, a 19yearold Chinese student, said goodbye to her family and friends in China and boarded (board) a plane for London six months ago in order to get a business qualification. She was ambitious(ambition) to set up a business after graduation. It was the first time that she had left (leave) home.At first, Xie Lei had to adapt to life in a different country. She chose to live with a host family, who can help with her adaptation (adapt) to the new culture. When she missed home, she felt comforted (comfort) to have a second family. Also Xie Lei had to satisfy academic requirements. Her tutor told her to acknowledge what other people had said if she cited their ideas, and advised her to read lots of information in order to form a wise opinion of her own.Now halfway through her exchange year, Xie Lei felt much more at home in the UK. She said engaging (engage) in British culture had helped and that she had been involved (involve) in social activities. She also said while learning about business, she was acting as a cultural messenger building a bridge between the two countries.
新人教版高中英语选修2Unit 2 Reading for writing教学设计
The theme of this section is to express people's views on studying abroad. With the continuous development of Chinese economic construction, especially the general improvement of people's living standards, the number of Chinese students studying abroad at their own expense is on the rise. Many students and parents turn their attention to the world and regard studying abroad as an effective way to improve their quality, broaden their horizons and master the world's advanced scientific knowledge, which is very important for the fever of going abroad. Studying abroad is also an important decision made by a family for their children. Therefore, it is of great social significance to discuss this issue. The theme of this section is the column discussion in the newspaper: the advantages and disadvantages of studying abroad. The discourse is about two parents' contribution letters on this issue. They respectively express their own positions. One thinks that the disadvantages outweigh the advantages, and the other thinks that the advantages outweigh the disadvantages. The two parents' arguments are well founded and logical. It is worth noting that the two authors do not express their views on studying abroad from an individual point of view, but from a national or even global point of view. These two articles have the characteristics of both letters and argumentative essays1.Guide the students to read these two articles, and understand the author's point of view and argument ideas2.Help the students to summarize the structure and writing methods of argumentative writing, and guides students to correctly understand the advantages and disadvantages of studying abroad3.Cultivate students' ability to analyze problems objectively, comprehensively and deeply
新人教版高中英语选修2Unit 4 Learning about Language教学设计
This section guides students to pay attention to the typical context of vocabulary use, helps students accumulate vocabulary around the key vocabulary of this unit, and uses the learned words and word chunks in different contexts to deeply understand their meaning and usage, so as to achieve the purpose of review and consolidation.The teaching design activities aim to guide students to pay attention to the typical context in which the target vocabulary is used, as well as the common vocabulary used in collocation, so that students can complete the sentence with correct words. In terms of vocabulary learning strategies, this unit focuses on cultivating students' ability to pay attention to collocation of words and to use word blocks to express meaning.For vocabulary learning, it is not enough just to know the meaning of a single word, but the most important thing is to master the common collocations of words, namely word blocks.Teachers should timely guide students to summarize common vocabulary collocation, such as verb and noun collocation, verb and preposition collocation, preposition and noun collocation, and so on.1. Guide students to understand and consolidate the meaning and usage of the vocabulary in the context, 2. Guide the students to use the unit topic vocabulary in a richer context3. Let the students sort out and accumulate the accumulated vocabulary, establishes the semantic connection between the vocabulary,4. Enable students to understand and master the vocabulary more effectivelyGuiding the Ss to use unit topic words and the sentence patterns in a richer context.
新人教版高中英语选修2Unit 5 Reading and thinking教学设计
The theme of this activity is to learn the first aid knowledge of burns. Burns is common in life, but there are some misunderstandings in manual treatment. This activity provides students with correct first aid methods, so as not to take them for granted in an emergency. This section guides students to analyze the causes of scald and help students avoid such things. From the perspective of text structure and collaborative features, the text is expository. Expository, with explanation as the main way of expression, transmits knowledge and information to readers by analyzing concepts and elaborating examples. This text arranges the information in logical order, clearly presents three parts of the content through the subtitle, accurately describes the causes, types, characteristics and first aid measures of burns, and some paragraphs use topic sentences to summarize the main idea, and the level is very clear.1. Guide students to understand the causes, types, characteristics and first aid methods of burns, through reading2. Enhance students’ ability to deal withburnss and their awareness of burns prevention3. Enable students to improve the ability to judge the types of texts accurately and to master the characteristics and writing techniques of expository texts.Guide students to understand the causes, types, characteristics and first aid methods of burns, through readingStep1: Lead in by discussing the related topic:1. What first-aid techniques do you know of ?CPR; mouth to mouth artificial respiration; the Heimlich Manoeuvre
新人教版高中英语选修2Unit 5 Using langauge-Listening教学设计
The theme of this section is to learn how to make emergency calls. Students should learn how to make emergency calls not only in China, but also in foreign countries in English, so that they can be prepared for future situations outside the home.The emergency telephone number is a vital hotline, which should be the most clear, rapid and effective communication with the acute operator.This section helps students to understand the emergency calls in some countries and the precautions for making emergency calls. Through the study of this section, students can accumulate common expressions and sentence patterns in this context. 1.Help students accumulate emergency telephone numbers in different countries and learn more about first aid2.Guide the students to understand the contents and instructions of the telephone, grasp the characteristics of the emergency telephone and the requirements of the emergency telephone.3.Guide students to understand the first aid instructions of the operators.4.Enable Ss to make simulated emergency calls with their partners in the language they have learned1. Instruct students to grasp the key information and important details of the dialogue.2. Instruct students to conduct a similar talk on the relevant topic.Step1:Look and discuss:Match the pictures below to the medical emergencies, and then discuss the questions in groups.
新人教版高中英语选修2Unit 4 Reading and thinking教学设计
【词汇精讲】highlight n.最好或最精彩的部分 vt.突出;强调;使醒目One of the highlights of the trip was seeing the Taj Mahal.这次旅行的亮点之一是参观泰姬陵。Your resume should highlight your skills and achievements.你的简历应该突出你的技能和成就。The report highlights the major problems facing society today.报告强调了当今社会所面临的主要问题。I’ve highlighted the important passages in yellow.我用黄色标出了重要段落。7.Edmonton is freezing cold in winter,with daily temperatures averaging -10 ℃.埃德蒙顿冬季寒冷,日平均气温为-10°C。【词汇精讲】freezing adj.极冷的;冰冻的Leave a basin of water outside in freezing weather.在冰冻的天气里,放一盆水在室外。It’s freezing cold outside so wear a warm coat.外面超冷的,所以穿一个暖和一点的外套吧。8.It was not until 9:30 a.m.that they finally reached the capital of Ontario,Toronto.直到上午9时30分,他们才终于到达多伦多的首府安大略省。【句式剖析】本句是一个强调句,强调的是句子的时间状语until 9:30。含有not...until...的句子的强调句为It is not until...that...,that后面的句子要用肯定形式。It was not until then that I suddenly realized nobody was happier than I was.直到那时我才突然意识到没有人比我更幸福了。