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新人教版高中英語必修2Unit 4 History and traditions教案
這個地區(qū)有著深厚的傳統(tǒng)。既學(xué)既練：為了讓更多的外國游客了解中國文化，欣賞中國美麗的自然風(fēng)光，感受中國發(fā)生的巨大變化，某外文雜志社將出版一本英語小冊子來介紹中國的旅游景點。該雜志社邀請你為該小冊子寫一篇英語短文來介紹杭州，內(nèi)容包括：1．杭州的位置(中國東南部)、面積(16 000多平方公里)及歷史(2 200多年)等；2．杭州的旅游特色(自然風(fēng)景、傳統(tǒng)文化、特色小吃等)；3．希望更多的游客來杭州參觀。注意：1．詞數(shù)80左右；2．可適當(dāng)增加細(xì)節(jié)，以使行文連貫。Located in the southeast of China, Hangzhou is a beautiful city．Dating back more than 2，200 years, Hangzhou covers an area of more than 16，000 square kilometers．In Hangzhou, you can visit the West Lake, whose scenery is fascinating．In addition, you can’t miss its cultural relics and historical sites, from which you will learn more about excellent Chinese traditional culture and traditions．In Hangzhou, the special snacks are famous and visitors from different parts of the world think highly of them．As a tourist attraction, Hangzhou attracts a large number of visitors from home and abroad every year．Once you come to China, Hangzhou is a scenic spot you can’t miss．
新人教版高中英語必修2Unit 5 Music-Listening＆Speaking＆Talking教案
choir memberspeople to run food stands people to sell festival ticketspeople to sell music CDspeople to set up equipmentmusical performersStep 2: Listen to the announcement again and answer the questions. ? 1. What kind of songs will Grace Davis sing at the festival?? 2. Who can try out as a performer?? 3. What can those who think they do not have musical talent do?? 4. How can students volunteer to take part?? Talking about preferences:? Would you prefer doing ..?? What would you prefer to do?? Would you rather do .... or ….?? What would you rather do?? I'd prefer .... to ..? I'd rather have ... than .. Step 3: Speaking ProjectWork in groups. Role-play the conversation or make a new one.? Debbie: Where have you been? You missed the announcement about the music festival.? John: I was at the doctor's office. Music festival?? Frank: Yes, it's going to be next month on the school sports field. John, you can play the piano. How about playing it at the festival?? John: Well, I'd rather play the violin. I can play Liang Zhu.? Frank: Wow! Sounds good. What about you, Debbie? ? Debbie: Actually, I don't have much musical ability. I'd prefer just to help out with the crowds.? Frank: You can sell tickets or work at a food stand.? John: So can I assume that the aim of the festival is to raise money?? Debbie: Yes. All of the money will go to charity.
新人教版高中英語必修2Unit 5 Music-Discovering Useful Structures教案一
Step1:自主探究。1．(教材P52)Born(bear) in the USA on 2 January 1970, Whitacre began studying music at the University of Nevada in 1988．2．(教材P52) Moved(move) by this music, he said, “It was like seeing color for the first time．”3．(教材P56)I was very afraid and I felt so alone and discouraged(discourage)．4．(教材P58)Encouraged(encourage) by this first performance and the positive reaction of the audience, I have continued to play the piano and enjoy it more every day．Step2:語法要點精析。用法1：過去分詞作表語1）．過去分詞可放在連系動詞be, get, feel, remain, seem, look, become等之后作表語，表示主語所處的狀態(tài)Tom was astonished to see a snake moving across the floor．湯姆很驚訝地看到一條蛇正爬過地板。Finally the baby felt tired of playing with those toys．終于嬰兒厭倦了玩那些玩具。注意：1）.過去分詞作表語時與被動語態(tài)的區(qū)別過去分詞作表語時，強(qiáng)調(diào)主語所處的狀態(tài)；而動詞的被動語態(tài)表示主語是動作的承受者，強(qiáng)調(diào)動作。The library is now closed．(狀態(tài))圖書館現(xiàn)在關(guān)閉了。The cup was broken by my little sister yesterday．(動作)昨天我妹妹把杯子打碎了。2）感覺類及物動詞的現(xiàn)在分詞與過去分詞作表語的區(qū)別過去分詞作表語多表示人自身的感受或事物自身的狀態(tài)，常譯作“感到……的”；現(xiàn)在分詞多表示事物具有的特性，常譯作“令人……的”。
新人教版高中英語必修2Unit 5 Music-Listening and Speaking教案
This lesson is about music. Students can classify the types of music through the instruments and its sound and can talk about their preferences about music, even join some activities and play a role in them according to their musical talents. On the basis, they are guided to use the languages to express their preferences and some plosive sounds and their rules.1. Classify the music types through the instruments and its sound.2. Listen and understand what the speakers’ preferences are and the reasons; talk about their own preferences and give their own reasons, using these sentences: “What kind of music do you like? And why? “ “Because it makes/gives me energy/peaceful.../touches my heart...”.3. Learn some plosives and the rules.4. Join some activities and play a role in them according to the talents. 1. Listen and understand what the speakers’ preferences are and the reasons;2. talk about their own preferences and give their own reasons, using these sentences: “What kind of music do you like? And why? “ “Because it makes/gives me energy/peaceful.../touches my heart...”.3. Learn some plosives and incomplete plosives and its rules.Step 1 Lead inPoint at the pictures on P50 and ask Q1: What are the people doing in the pictures below?Q2: What kind of music they are?Then play the MP3s one by oneStep 2 ListeningTask 1: A reporter from the school newspaper is interviewing students about music. Listen to the interviews. Draw lines between the words to make complete sentences. Some words will not be used.
新人教版高中英語必修2Unit 5 Music-Reading and Thinking教案一
This section focuses on "learning about experiencing music Online". This virtual choir is a new form of music performance. Members from all over the world don't need to love to come to a place. Instead, they use the new technology to model the various parts and wonderful virtual harmony group of music in the family. Students need to understand the main meaning of each paragraph. Finding topic sentences is an important way to understand the general idea of a paragraph. After the topic sentence, it is usually the detail sentence that supports and explains the topic sentence. Some paragraphs have obvious subject sentences, for example, the first sentence of the second paragraph is the subject sentence of the paragraph, and the following sentenceStudents need to pay attention to the topic sentences and key sentences, and then pay attention to how the sentences after the meaning explain, explain and support the topic sentences or key sentences before.1.Guide students to learn about experiencing music online2.Guide students to scan and circle the information in the text.3.Guide students to find the numbers and dates to fill in the timeline.4.Guide students to learn more about music by completing the sentences with the correct forms of the words and phrases. And then make a mind map about the outline of the passage.1. Guide students to pay attention to reading strategies, such as prediction, self-questioning and scanning.2. Help students sort out the main meaning of each paragraph and understand the narrative characteristics of "timeline” in illustrative style.3. Lead students to understand the changes that have been caused by the Internet.
新人教版高中英語必修2Unit 1 Cultural Heritage-Reading For Writing教案
This report is short, concise and has typical news content and language features. The title uses the verb phrases, embodying the characteristics of being concise and general. The introduction is the first two sentences in the first paragraph, describing the general situation of the cultural heritage protection project, including time, place, characters, events and other news elements, so that readers can see the main points of the news report at a glance. The main body is the second and third paragraphs, which report the important historical and cultural value of Mogao Grottoes and the production of Mogao Grottoes Material digital photos, which are of great significance to the inheritance of historical culture and the promotion of international cultural understanding, exchange and cooperation. Direct citation is used in the report, as well as background introduction and other news writing techniques.1. Get students to have a good understanding of some features about a news report by reading the text.2. Instruct students to write a summary about a news report properly using some newly acquired writing skills in this period.3. Develop students’ writing and cooperating abilities.4. Strengthen students’ great interest in writing discourses.1. Stimulate students to have a good understanding of how to a summary about a news report 2. Cultivate students to write a news report properly and concisely.Step 1: Lead in Do you think it is necessary for us to circulate our cultural heritage to the world? Why or why not?Do we need to learn more about other countries’ cultural heritage? Why or why not?Step 2: Read to discover details concerning the main body of the news report.
新人教版高中英語必修2Unit 4 History and Traditions-Reading for Writing教案
Step 1 Lead inThere are many interest of places in the UK. What do you know ?The Big Ben the London Tower the Thames RiverStep 2 Before reading---analyze the titleBeautiful Ireland and its traditionWe know that the article mainly tells about the beauty and traditions of Ireland. Step 3 While reading---Task 1Read the text and answer the following questions.Q1: What makes the Irish countryside exciting and inspiring?Its beauty and how it offers something for all the scenes.Q2: What are the best ways to experience some Irish traditions and cultures?By stopping by a village pub and relaxing with a drink and traditional meal while listening to music and watching dancingQ3: What is the meaning of “breathe in the sweet scent of fresh flowers while birds greet the new day with their morning song ?”It means to not just smell but also breathe in the smell of fresh flowers early in the morning as the birds sing their first song of the new day.Q4: What are the best ways to experience Chinese traditions and customs ?By travelling to different places and using all your senses to experience everything and by interacting with local people.Step 4 While reading---Task 2Analyze the descriptive paragraph1. Identify and underline the paragraph’s introductory sentence and the ending sentence.Introductory sentence: Ireland’s beautiful countryside has always had a great influence on its people and traditions.Ending sentence: And if you introduce yourself to a friendly face, you are more than likely to experience local culture and customs first-hand.2. The paragraph talks about different senses in different places. Write the senses and places in the order that they appear.
高中教師個人教學(xué)工作計劃5篇
二、學(xué)情分析 在校領(lǐng)導(dǎo)的正確領(lǐng)導(dǎo)下，本學(xué)期我校生源比去年有了重大的變化.高一年級招收了400多名新生，學(xué)校帶來了新的希望.然而，我清醒地認(rèn)識到任重而道遠(yuǎn)的現(xiàn)實是，我校實驗班分?jǐn)?shù)線僅為140分，普通班入學(xué)成績?nèi)跃痈浇髦袑W(xué)之末.要實現(xiàn)我校教學(xué)質(zhì)量的根本性進(jìn)步，非一朝一夕之功.實驗班的教學(xué)當(dāng)然是重中之重，而普通班又絕不能一棄了之.現(xiàn)在的學(xué)情與現(xiàn)實決定了并不是付出十分努力就一定有十分收獲.但教師的責(zé)任與職業(yè)道德時刻提醒我，沒有付出一定是沒有收獲的.作為新時代的教師，只有付出百倍的努力，苦干加巧干，才能對得起良心，對得起人民群眾的期望.
統(tǒng)編版二年級語文上第3課植物媽媽有辦法教學(xué)設(shè)計教案
《植物媽媽有辦法》是統(tǒng)編版二年級上冊第一單元的一篇講述植物傳播種子的詩歌，作者運用比喻和擬人的修辭手法，以富有韻律感的語言，生動形象地介紹了蒲公英、蒼耳、豌豆傳播種子的方法。從植物媽媽的辦法中，能感到大自然的奇妙，激發(fā)學(xué)生了解更多的植物知識的愿望，培養(yǎng)學(xué)生留心觀察身邊事物的習(xí)慣。教學(xué)過程中，可以將課文插圖與詩句相配合，感受三種植物傳播種子的方式。課文插圖畫面鮮活、直觀、富有兒童情趣，既能激發(fā)學(xué)生的學(xué)習(xí)熱情，又能輔助學(xué)生認(rèn)識事物，理解重點詞句。 1.認(rèn)識“植、如”等12個生字，會寫“法、如”等10個生字，讀準(zhǔn)多音字“為”和“得”。2.正確、流利、有感情地朗讀課文，背誦課文。3.了解蒲公英、蒼耳、豌豆三種植物傳播種子的方法。4.激發(fā)學(xué)生觀察植物、了解植物知識、探究植物奧秘的興趣。 1.教學(xué)重點：正確、流利、有感情地朗讀課文，背誦課文。了解蒲公英、蒼耳、豌豆三種植物傳播種子的方法。2.教學(xué)難點：激發(fā)學(xué)生觀察植物、了解植物知識、探究植物奧秘的興趣。 2課時
人教版高中數(shù)學(xué)選修3分類加法計數(shù)原理與分步乘法計數(shù)原理(2)教學(xué)設(shè)計
當(dāng)A,C顏色相同時,先染P有4種方法,再染A,C有3種方法,然后染B有2種方法,最后染D也有2種方法.根據(jù)分步乘法計數(shù)原理知,共有4×3×2×2=48(種)方法;當(dāng)A,C顏色不相同時,先染P有4種方法,再染A有3種方法,然后染C有2種方法,最后染B,D都有1種方法.根據(jù)分步乘法計數(shù)原理知,共有4×3×2×1×1=24(種)方法.綜上,共有48+24=72(種)方法.故選B.答案:B5.某藝術(shù)小組有9人,每人至少會鋼琴和小號中的一種樂器,其中7人會鋼琴,3人會小號,從中選出會鋼琴與會小號的各1人,有多少種不同的選法?解:由題意可知,在藝術(shù)小組9人中,有且僅有1人既會鋼琴又會小號(把該人記為甲),只會鋼琴的有6人,只會小號的有2人.把從中選出會鋼琴與會小號各1人的方法分為兩類.第1類,甲入選,另1人只需從其他8人中任選1人,故這類選法共8種;第2類,甲不入選,則會鋼琴的只能從6個只會鋼琴的人中選出,有6種不同的選法,會小號的也只能從只會小號的2人中選出,有2種不同的選法,所以這類選法共有6×2=12(種).因此共有8+12=20(種)不同的選法.
初中數(shù)學(xué)人教版二元一次方程組教學(xué)設(shè)計教案
（一）例題引入籃球聯(lián)賽中，每場比賽都要分出勝負(fù)，每隊勝1場得2分，負(fù)1場得1分。某隊在10場比賽中得到16分，那么這個隊勝負(fù)場數(shù)分別是多少？方法一：（利用之前的知識，學(xué)生自己列出并求解）解：設(shè)剩X場，則負(fù)（10－X)場。方程：2X+(10－X)=16方法二：（老師帶領(lǐng)學(xué)生一起列出方程組）解：設(shè)勝X場，負(fù)Y場。根據(jù)：勝的場數(shù)+負(fù)的場數(shù)=總場數(shù) 勝場積分+負(fù)場積分=總積分得到：X+Y=10 2X+Y=16
新人教版高中英語必修1Unit 3 Sports and Fitness-Reading for Writing教案
Then have them write a short paragraph to describe and explain their changes. After that, get the Ss to exchange their drafts with their partners and use the checklist to give feedback on their drafts, and finally revise it.Step 5 Summary of how to write a wellness book1.健康書的審題步驟：第一步：明確要求該寫作屬于經(jīng)驗分享，故要用第一人稱來寫;時態(tài)以一股現(xiàn)在時為主。第二步：確定段落該類文章可以從以下三個方面人手:Para.1首先表明寫作的目的Para.2自己的做法及心得體會Para.3表示期望及感謝第三步：提煉要點2.健康書常見句式：1) It is an honor for me to share my favorite sport with you,2) It makes me feel relaxed playing with my friends.3) It makes me rid myself of stress while playing with my friends.4) Moreover, it provides me a valuable chance to communicate with others.5) I we eat too little or too much, or if we choose the wrong food, we may become sick.6) We can do something to change the poor situation.Step 6Homework假如你的老師讓你在班級Wellness Bok上分享自己的親身經(jīng)歷及心得，請根據(jù)以下要點寫一篇80字左右的文章1. 你喜歡的運動是什么？2. 你最喜歡的原因是什么？3. 你參加鍛煉的體會。
新人教版高中英語必修1Unit 3 Sports and Fitness-Reading and Thinking教案
2. Sort out detailed information about Michael Jordan.（1） Understand the transitional sentence.Q: Which part is about Michael Jordan as a master? Which part is about the example he set?（2） Have the Ss Focus on why Michael Jordan is a master and what good examples Michael Jordan set when they’re reading. And think about these questions as below:Q1: How does the author describe his impressive skills?Q2: How do you understand “time seemed to stand still”?Q3: What does “graceful” mean?Q4. Which sentence do you think best describes his mental strength?Q5. Which words is important in the sentence in describing his mental strength? Why?Q6: How do you understand “unique”?Q7: What can we learn from Michael Jordan?Step 5 Discussing and recommendingRecommend their own living legends of sports.Work in groups to choose your own living legend of sports and give the reasons of your choice. Step 6 HomeworkReview the stories of Lang Ping and Michael Jordan, and try to retell them.
人教版新課標(biāo)PEP小學(xué)英語三年級上冊Look at me教案（全英文版）
３、Practicea. Nice to meet you. Nice to meet you,too.b. Perform the dialogue.c. Arrange the dialogue according to the pictures or sentence cards.d. Let’s play.A: Good afternoon,B. This is C. Hello, C! Nice to meet you.C: Nice to meet you, too.A,B: Goodbye!C: Bye!４、Assessment Workbook page 10Add-activitiesa. Listen to the recording and repeat.b. Make a dialogue according to "Let’s talk".Second Period一、Teaching contents1. Let’s learn Words：body, leg, arm, hand, finger, foot.1. Let’s do二、Preparation１、a puppet２、Cards of body, leg, arm, hand, finger and foot.３、headgear of a captain三、Teaching steps１、Warm-up/ Revisiona. Captain says to review "let’s do" of Part A.b. Perform the students their own dialogues.２、Presentationa. Learn to say "body, leg, arm, hand, finger and foot."b. Listen to the recording and repeat.c. Let’s do. Clap your hands. Snap your fingers. Wave your arms. Cross your legs. Shake your body. Stamp your foot.３、Practicea. Let’s draw a person.b. Let’s do. Point out which picture.c. Let’s do. Who responses faster.４、Assessment Workbook page 11５、Add-activitiesa. Listen to the recording, repeat and act out.b. Say all the names of the body to your parents.Third Period一、Teaching contents1. Let’s check2. Let’s chant二、Preparation１、stationeries１、pictures of parts of Zoom
人教版新課標(biāo)PEP小學(xué)英語三年級上冊Happy Birthday（全英文版）說課稿
1. Do some exercise on the paper. There are four kinds of exercise here. The exercise 1 is to develop Ss’ ability of listening. Exercise 2 is to practice Ss’ ability of knowing the words. Exercise 3 is to develop Ss’ ability of speaking numbers and letters. Exercise 4 is to make Ss know the words and letters well. These exercises can consolidate the new knowledge from different styles of problems.2. Then tell Ss that we can sing the numbers like “ Do, re, mi, fa, so, la, ti, do” and let them listen to a song named “Do, Re, Mi”. Add some extra knowledge so that Ss will be glad to see that the numbers can be used in another way.Step 4 Homework1.Read the numbers from 1 to 7 and 7 to 1 five times.2.Read the letters “u, v, w” five times follow the tape.Reading is a useful way for the Ss of Grade One to practice the knowledge. Ask Ss to imitate reading from the tape in order to make Ss have a good habit of listening and let them have a better pronunciation.Step 5 Board writingI ‘ll put the seven numbers like a scale(音階)as I’ll let Ss know that we can sing out the numbers. When it comes to listen to the song, I ‘ll draw a musical note on Bb. Unit 9 Happy birthday!sevensixfivefourthree U u V v W wtwo pupil five windowoneThat’s all for my class designing. Thank you for listening!
人教A版高中數(shù)學(xué)必修一單調(diào)性與最大（小）值教學(xué)設(shè)計（1）
《函數(shù)的單調(diào)性與最大（?。┲祡》系人教A版高中數(shù)學(xué)必修第一冊第三章第二節(jié)的內(nèi)容,本節(jié)包括函數(shù)的單調(diào)性的定義與判斷及其證明、函數(shù)最大（?。┲档那蠓āＴ诔踔袑W(xué)習(xí)函數(shù)時,借助圖像的直觀性研究了一些函數(shù)的增減性,這節(jié)內(nèi)容是初中有關(guān)內(nèi)容的深化、延伸和提高函數(shù)的單調(diào)性是函數(shù)眾多性質(zhì)中的重要性質(zhì)之一,函數(shù)的單調(diào)性一節(jié)中的知識是前一節(jié)內(nèi)容函數(shù)的概念和圖像知識的延續(xù),它和后面的函數(shù)奇偶性,合稱為函數(shù)的簡單性質(zhì),是今后研究指數(shù)函數(shù)、對數(shù)函數(shù)、冪函數(shù)及其他函數(shù)單調(diào)性的理論基礎(chǔ);在解決函數(shù)值域、定義域、不等式、比較兩數(shù)大小等具體問需用到函數(shù)的單調(diào)性;同時在這一節(jié)中利用函數(shù)圖象來研究函數(shù)性質(zhì)的救開結(jié)合思想將貫穿于我們整個高中數(shù)學(xué)教學(xué)。
【高教版】中職數(shù)學(xué)拓展模塊：2.3《拋物線》教學(xué)設(shè)計
一、教學(xué)目標(biāo)(一)知識教育點使學(xué)生掌握拋物線的定義、拋物線的標(biāo)準(zhǔn)方程及其推導(dǎo)過程．(二)能力訓(xùn)練點要求學(xué)生進(jìn)一步熟練掌握解析幾何的基本思想方法，提高分析、對比、概括、轉(zhuǎn)化等方面的能力．(三)學(xué)科滲透點通過一個簡單實驗引入拋物線的定義，可以對學(xué)生進(jìn)行理論來源于實踐的辯證唯物主義思想教育．二、教材分析1．重點：拋物線的定義和標(biāo)準(zhǔn)方程．2．難點：拋物線的標(biāo)準(zhǔn)方程的推導(dǎo)．三、活動設(shè)計提問、回顧、實驗、講解、板演、歸納表格．四、教學(xué)過程(一)導(dǎo)出課題我們已學(xué)習(xí)了圓、橢圓、雙曲線三種圓錐曲線．今天我們將學(xué)習(xí)第四種圓錐曲線——拋物線，以及它的定義和標(biāo)準(zhǔn)方程．課題是“拋物線及其標(biāo)準(zhǔn)方程”．首先，利用籃球和排球的運動軌跡給出拋物線的實際意義，再利用太陽灶和拋物線型的橋說明拋物線的實際用途。
【高教版】中職數(shù)學(xué)拓展模塊：3.5《正態(tài)分布》教學(xué)設(shè)計
教學(xué)目的：理解并熟練掌握正態(tài)分布的密度函數(shù)、分布函數(shù)、數(shù)字特征及線性性質(zhì)。教學(xué)重點：正態(tài)分布的密度函數(shù)和分布函數(shù)。教學(xué)難點：正態(tài)分布密度曲線的特征及正態(tài)分布的線性性質(zhì)。教學(xué)學(xué)時：2學(xué)時教學(xué)過程:第四章 正態(tài)分布§4.1 正態(tài)分布的概率密度與分布函數(shù)在討論正態(tài)分布之前，我們先計算積分。首先計算。因為(利用極坐標(biāo)計算)所以。記，則利用定積分的換元法有因為，所以它可以作為某個連續(xù)隨機(jī)變量的概率密度函數(shù)。定義 如果連續(xù)隨機(jī)變量的概率密度為則稱隨機(jī)變量服從正態(tài)分布,記作,其中是正態(tài)分布的參數(shù)。正態(tài)分布也稱為高斯（Gauss）分布。
【高教版】中職數(shù)學(xué)拓展模塊：2.2《雙曲線》教學(xué)設(shè)計
教學(xué)準(zhǔn)備 1. 教學(xué)目標(biāo) 知識與技能掌握雙曲線的定義，掌握雙曲線的四種標(biāo)準(zhǔn)方程形式及其對應(yīng)的焦點、準(zhǔn)線．過程與方法掌握對雙曲線標(biāo)準(zhǔn)方程的推導(dǎo)，進(jìn)一步理解求曲線方程的方法——坐標(biāo)法．通過本節(jié)課的學(xué)習(xí)，提高學(xué)生觀察、類比、分析和概括的能力．情感、態(tài)度與價值觀通過本節(jié)的學(xué)習(xí)，體驗研究解析幾何的基本思想，感受圓錐曲線在刻畫現(xiàn)實和解決實際問題中的作用，進(jìn)一步體會數(shù)形結(jié)合的思想．2. 教學(xué)重點/難點 教學(xué)重點雙曲線的定義及焦點及雙曲線標(biāo)準(zhǔn)方程．教學(xué)難點在推導(dǎo)雙曲線標(biāo)準(zhǔn)方程的過程中，如何選擇適當(dāng)?shù)淖鴺?biāo)系． 3. 教學(xué)用具 多媒體4. 標(biāo)簽
高教版中職數(shù)學(xué)基礎(chǔ)模塊下冊：8.4《圓》教學(xué)設(shè)計
教 學(xué) 過 程教師 行為學(xué)生 行為教學(xué) 意圖時間 *揭示課題 8．4 圓（二） *創(chuàng)設(shè)情境 興趣導(dǎo)入 【知識回顧】 我們知道，平面內(nèi)直線與圓的位置關(guān)系有三種（如圖8-21）： （1）相離：無交點； （2）相切：僅有一個交點； （3）相交：有兩個交點． 并且知道，直線與圓的位置關(guān)系，可以由圓心到直線的距離d與半徑r的關(guān)系來判別（如圖8-22）： （1）：直線與圓相離； （2）：直線與圓相切； （3）：直線與圓相交. 介紹 講解 說明 質(zhì)疑 引導(dǎo) 分析 了解 思考 思考 帶領(lǐng) 學(xué)生 分析 啟發(fā) 學(xué)生思考 0 15*動腦思考 探索新知 【新知識】 設(shè)圓的標(biāo)準(zhǔn)方程為 ， 則圓心C(a，b)到直線的距離為 ． 比較d與r的大小，就可以判斷直線與圓的位置關(guān)系． 講解 說明 引領(lǐng) 分析 思考 理解 帶領(lǐng) 學(xué)生 分析 30*鞏固知識 典型例題 【知識鞏固】 例6 判斷下列各直線與圓的位置關(guān)系： ⑴直線, 圓； ⑵直線,圓． 解?、?由方程知，圓C的半徑，圓心為． 圓心C到直線的距離為 , 由于，故直線與圓相交． ⑵ 將方程化成圓的標(biāo)準(zhǔn)方程，得 ． 因此，圓心為，半徑．圓心C到直線的距離為 , 即由于，所以直線與圓相交． 【想一想】 你是否可以找到判斷直線與圓的位置關(guān)系的其他方法？ *例7 過點作圓的切線，試求切線方程． 分析 求切線方程的關(guān)鍵是求出切線的斜率．可以利用原點到切線的距離等于半徑的條件來確定． 解 設(shè)所求切線的斜率為，則切線方程為 ， 即 ． 圓的標(biāo)準(zhǔn)方程為 ， 所以圓心，半徑． 圖8－23 圓心到切線的距離為 ， 由于圓心到切線的距離與半徑相等，所以 ， 解得 ． 故所求切線方程（如圖8-23）為 ， 即 或． 說明 例題7中所使用的方法是待定系數(shù)法，在利用代數(shù)方法研究幾何問題中有著廣泛的應(yīng)用． 【想一想】 能否利用“切線垂直于過切點的半徑”的幾何性質(zhì)求出切線方程？ 說明 強(qiáng)調(diào) 引領(lǐng) 講解 說明 引領(lǐng) 講解 說明 觀察 思考 主動 求解 思考 主動 求解 通過例題進(jìn)一步領(lǐng)會 注意 觀察 學(xué)生 是否 理解 知識 點 50
