杨浦区高中补习班最好的高中补习机构恒高一对一高中数学资料
- 格式:docx
- 大小:67.73 KB
- 文档页数:2
yxO杨浦新王牌一元二次不等式的解法一、复习1、一元一次不等式的解法依据是不等式的基本性质3(乘法性质):如果0,>>c b a ,那么bc ac >;如果0,<>c b a ,那么bc ac <.2、二次函数()02≠++=a c bx ax y 的图像。
二、新课(一)一元二次不等式的定义1、只含有 未知数,并且未知数的最高次数是 的 不等式叫做一元二次不等式。
2、一元二次不等式的一般形式为: 。
(二)一元二次不等式的解法探究 1、如何解一元二次不等式0322>--x x ?解法一:先分解因式,转化为一元一次不等式组求解。
解法二:求此不等式的的解集可看作求二次函数322--=x x y 取正值时x 的取值范围,即求该二次函数的图像在x 轴上方时x 的取值范围。
2、根据二次函数322--=x x y 的图像,得 一元二次不等式0322<--x x 的解集是 ; 一元二次不等式0322≥--x x 的解集是 ; 一元二次不等式0322≤--x x的解集是 。
3、已知一元二次方程02=++c bx ax 的根的判别式042>-=∆ac b , 则此方程有两个不等实数根,不妨设为21,x x ,且21x x <, 作出对应二次函数c bx ax y ++=2的图像,由图可得:一元二次不等式)0(02>>++a c bx ax 的解集是 ; 一元二次不等式)0(02><++a c bx ax 的解集是 ;【拓展】若0<a ,则一元二次不等式02>++c bx ax 的解集是 ;一元二次不等式02<++c bx ax 的解集是 。
(三)用区间表示不等式的解集设b a 、都为实数,并且b a <,我们规定: (1)集合}|{b x a x ≤≤叫做 区间,表示为 ; (2)集合}|{b x a x <<叫做 区间,表示为 ;(3)集合}|{b x a x <≤或}|{b x a x ≤<叫做 区间,分别表示为 或 ; (4)实数集R 表示为 ;集合}|{a x x ≥表示为 ; 集合}|{a x x >表示为 ;集合}|{b x x ≤表示为 ; 集合}|{b x x <表示为 ;在上述所有的区间中,b a 、叫做区间的 ; “∞-”读作“负无穷大”,“∞+”读作“正无穷大”。
杨浦新王牌学员日校: 年 级:高一 课时数:2学员姓名: 辅导科目: 数学 学科教师:王老师课 题 幂函数和指数函数授课日期及时段教学目的1、掌握一些常见幂函数的图像和性质2、掌握指数函数的图像和性质3、能利用幂函数和指数函数解决一些常见问题教学内容一.【知识精要】<1>幂函数: 形如:)(Q k x y k∈=常用幂函数性质及其图像性质如下:(1)0>k 时,幂函数的图象形如抛物线且恒通过原点)0,0(和)1,1(;0<k 时,幂函数的图象形如双曲线 且恒通过)1,1((2)0>k 时,幂函数的图象在区间),0[+∞上是增函数.特别地,当1>k 时,幂函数的图象上扬;当10<<k 时,幂函数的图象下杨;0<k 时,幂函数的图象在区间),0(+∞上是减函数(3)幂函数在第一象限必有图像,在第四象限必没有图像,其它象限图像根据函数奇偶性四.【巩固训练】 (1)函数y =1-11-x 的图象是( )(2)如图为指数函数xxxxd y c y b y a y ====)4(,)3(,)2(,)1(,则d c b a ,,,与1的大小关系为 ( ).A d c b a <<<<1 .B c d a b <<<<1 .C d c b a <<<<1 .D c d b a <<<<1(3)已知集合{}11M =-,,11242x N xx +⎧⎫=<<∈⎨⎬⎩⎭Z ,,则M N =I ( ).A {}11-, .B {}1- .C {}0.D {}10-,(4)若函数m y x +=+-12的图象不经过第一象限,则m 的取值范围是 ( ).A 2-≤m .B 2-≥m .C 1-≤m .D 1-≥m(5)已知222)(xx x f --=,则下列正确的是( )A .奇函数,在R 上为增函数B .偶函数,在R 上为增函数C .奇函数,在R 上为减函数D .偶函数,在R 上为减函数(6)方程1349+⋅-x x+27=0的解的平方和是(7)幂函数mx m m y )33(2--=在区间()+∞,0上是减函数,则m 的取值范围 (8)若函数|1|()2x f x m --=-的图象与x 轴有交点,则实数m 的范围是Oxya dc b(9)①函数xx x f 22)51()(-=的单调递增区间 ,值域②函数2323x y -=的单调递减区间 ,值域 ③函数)13()31(1822≤≤-=+--x y x x 的单调递增区间 ,值域(10)已知幂函数97222)199(--+-=m mx m m y 的图像不过原点,则m 的值为(11)一批设备价值a 万元,由于使用磨损,每年比上一年价值降低%b ,则n 年后这批设备的价值为 (12)若关于x 的指数方程043)4(9=+⋅++xxa 有实数解,则a 的取值范围 (13)设1,0≠>a a ,如果函数122-⋅+=x xa a y 在[]1,1-上的最大值为14,求a 的值(14)已知[]2,3-∈x ,求12141)(+-=x x x f 的最小值与最大值 五.【课后作业】(1)二次函数2y ax bx =+与指数函数()xby a=的图象只可为( )(2)设函数)(x f 定义在实数集上,它的图像关于直线1=x 对称,且当1≥x 时,13)(-=xx f ,则有( ))32()23()31(.f f f A << )31()23()32(.f f f B <<)23()31()32(.f f f C << )31()32()23(.f f f D <<(3)若幂函数dcbax y x y x y x y ====,,,在同一坐标系中的图象如下,则d c b a ,,,的大小关系是( ) A 、d >c >b >aB 、a >b >c >dC 、d >c >a >bD 、a >b >d >c。
杨浦新王牌一.【知识回顾】<1>向量的相关概念:1.向量的概念:既有大小又有方向的量(注意向量和数量的区别) (1)向量的基本要素:大小和方向.(2)向量的表示:几何表示法AB u u u r ;符号表示法a ;坐标表示法),(y x j y i x a(3)向量的长度:即向量的大小,记作|a|.2.零向量:长度为0的向量叫零向量,记作0,注意零向量的方向是任意的;3.单位向量:长度为一个单位长度的向量叫做单位向量(与AB u u u r 共线的单位向量是||AB AB );4.相等向量:长度相等且方向相同的两个向量叫相等向量,相等向量有传递性;),(),(2211y x y x 2121y y x x5.平行向量(也叫共线向量):方向相同或相反的非零向量a 、b 叫做平行向量,记作:a ∥b,【注:①相等向量一定是共线向量,但共线向量不一定相等;②两个向量平行与与两条直线平行是不同的两个概念:两个向量平行包含两个向量共线, 但两条直线平行不包含两条直线重合;③平行向量无传递性!(因有0r),规定零向量和任何向量平行;④三点A B C 、、共线 AB AC u u u r u u u r、共线;】6.相反向量:长度相等方向相反的向量叫做相反向量。
a 的相反向量是a.<2>向量的运算:向量的加减法,数与向量的乘积,向量的数量积(内积或点积)及其各运算的坐标表示和性质:<3>重要定理、公式:(1) 平面向量基本定理:21,e e是同一平面内两个不共线的向量,那么,对于这个平面内任一向量,有且仅有一对实数21, ,使2211e e a(2)两个向量平行的充要条件a ∥b a=b 01221 y x y x(3)两个向量垂直的充要条件a ⊥b a ·b=O 02121 y y x x(4)线段的定比分点公式设点P 分有向线段21P P 所成的比为 ,即P P 1=2PP ,则OP =111OP +112OP (线段的定比分点的向量公式).1,12121y y y x x x (线段定比分点的坐标公式) 当1 时,得中点公式:OP =21(1OP +2OP )或.2,22121y y y x x x二.【热身练习】(1)若向量a r ,b r 满足12a b r r ,且a r 与b r 的夹角为3,则a b r r _____________ (2)设向量(12)(23) ,,,a b ,若向量 a b 与向量(47) ,c 共线,则 _____________(3)a r ,b r 的夹角为120 ,1a r ,3b r 则5a b r r_____________(4)已知平面向量(2,4)a r ,(1,2)b r .若()c a a b b r r r r r ,则||c r_____________(5)在平行四边形ABCD 中,AC 为一条对角线,若(2,4)AB u u u r ,(1,3)AC u u u r ,则BD u u u r_____________ (6)已知向量a 与b 的夹角为120o,且4 a b ,那么)2(b a b的值为_____________三.【例题讲解】A CBDEA .2133b cB .5233c b C .2133b cD .1233b c (2)在平行四边形ABCD 中,AC 与BD 交于点O E ,是线段OD 的中点,AE 的延长线与CD 交于点F .若AC u u u r a ,BD u u u r b ,则AF u u u r( )A .1142 a b B .2133a bC .1124 a bD .1233 a b (3)设D 、E 、F 分别是△ABC 的三边BC 、CA 、AB 上的点,且2,DC BD u u u r u u u r 2,CE EA u u u r u u u r 2,AF FB u u u r u u u r则AD BE CF u u u r u u u r u u u r 与BC uuu r( )A.反向平行B.同向平行C.互相垂直D.既不平行也不垂直(4)设D 是ABC 边BC 延长线上一点,记AC AB AD )1( .若关于x 的方程22sin (1)sin 10x x 在[0,2) 上恰有两解,则实数 的取值范围是( )A. 2B. 4C. 122D. 4 或122(5)已知22,,1A B C x y 是圆上不同的三个点,0OA OB u u u r u u u r ,若存在, 实数使得OC u u u r=OA OB u u u r u u u r ,则, 的关系为( )A . 221 ;B .111;C .1 ;D . 1 .<7> <8>(6)(C 闵行)(理)如图,△ABC 中,4AB ,AC =8, 60 BAC ,延长CB 到D ,使BA BD ,当E 点在线段AD上移动时,若AC AB AE ,则 t 的最大值是 .(7)(C 崇明)给定两个长度为1的平面向量OA 和OB ,它们的夹角为 120.如图所示,点C 在以O 为圆心的圆弧AB 上变动.若OB y OA x OC ,其中R y x ,,则y x 的取值范围是BCOA。
力与物体平衡等级考训练一、单选题1.(2014·山东理综,14)如图,用两根等长轻绳将木板悬挂在竖直木桩上等高的两点,制成一简易秋千。
某次维修时将两轻绳各剪去一小段,但仍保持等长且悬挂点不变。
木板静止时,F 1表示木板所受合力的大小,F 2表示单根轻绳对木板拉力的大小,则维修后()A .F 1不变,F 2变大B.F 1不变,F 2变小C .F 1变大,F 2变大D .F 1变小,F 2变小2.如图,三根轻绳分别连接于C 、D 两点,A 、B 两端被悬挂在水平天花板上.现在C 点悬挂重物后,在D 点施加一个力可使CD 绳保持水平,为使此力最小,施力的方向应该()A .沿垂直BD 方向B .沿垂直CD 方向C .沿平行AB 方向D .沿CD 方向3.如图所示,斜面小车M 静止在光滑水平面上,一边紧贴墙壁。
若再在斜面上加一物体m ,且M 、m 相对静止,则此时小车受力个数为()(A )6(B )5(C )4(D )34.如图,倾斜固定直杆与水平方向成60°角,直杆上套有一个圆环,圆环通过一根细线与一只小球相连接.当圆环沿直杆下滑时,小球与圆环保持相对静止细线伸直,且与竖直方向成30°角.下列说法中正确的是()(A )圆环不一定加速下滑(B )圆环可能匀速下滑(C )圆环与杆之间一定没有摩擦(D )圆环与杆之间一定存在摩擦5.杂技表演的安全网如图(a )所示,网绳的结构为正方形格子,O 、a 、b 、c 、d……等为网绳的结点,安全网水平张紧后,若质量为m 的运动员从高处落下,并停止在O 点上。
该处下凹至最低点时,网绳dOe ,bOg 均为120°张角,如图(b )所示,此时O 点周围每根网绳承受的张力大小为()A .mg 21B .mg 23C .mg 2D .mgABCDa b c d O e fg h(a )(b )120o deP α α Q ’OQ6.如图,楔形物A 静置在水平地面上,其斜面粗糙,斜面上有小物块B 。
例题7.The situation in Iraq is so dangerous our government has _________ the worker ________there.A. forbidden, to goB. demanded, not to goC. kept, goingD. required, not going例题8.In our childhood, we were often _____ by our strict Grandma to pay attention to our table manners.A. demandedB. remindedC. allowedD. hoped44.Insist vt.1)Insist on doing2)My daughter insists on having dinner before 6 o’clock.3)Indians insist that they should not use paper in the toilet.4)Indians insist that using water is better than paper.例题1.The man insisted ________ a taxi for me even though I told him I lived nearby.A.findB. to findC.on findingD.in finding例题2.The old man insisted that the young man ____ his money and ____ to the policeman.A.had stolen; be sentB. should steal; should be sentC. had stolen; was sentD. should steal; was sent45.reward vt.1)Mother rewarded me ______ an IPAD.2)I was rewarded _______ the good exam results.46.rewarding adj.1)The discussion between the United States and China has been rewarding.2)Papa gave me a camera and a lot of $$$ today. It is a rewarding day.47.Mean adj. Vt.1)In Venezuela, having a surgery means being positive towards life.2)With her beauty, Stefania was meant to be Miss Universe.3)Many people in Asia mean to go to Venezuela for better appearance every year.4)Some South American women are meant for the Venezuelan Beauty Pageant (选美比赛).5)They say Sousa is very mean to those girls.6)the means of …7)_____ means of …8)by all means9)by no means48.meanwhile adv. = in the meantime例题1.Your plan means __________ more money, while I mean __________ it.A. losing; changingB. losing; to changeC. to lose; changingD. to lose; to change例题2.高一完型: In China, ranking (排名) students according to their examination as a means ofencouraging students to study harder.()46.A. has used B. has been usedC. has treatedD. has looked on例题3.Student loan is supposed to provide financial support for people who would __not be able to go to college .A. thereforeB. meanwhileC. neverthelessD. otherwise例题4.Every possible means ____to prevent the air pollution ,but the sky is still not clear.A. is usedB. has been usedC. had been usedD. are used例题5.I'm sorry I didn't mean ________ you.A.hurtB. to hurtC. hurtingD. having hurt例题6.---Let's have a chat over the coming football matches,shall we?-----Sorry. I am tired,and I ______ going to bed.A.would likeB.meanC.intendD.feel like例题7.It's too late to go out now. ________, it's starting to rain.A.BesidesB. MeanwhileC. HoweverD. Anyhow例题8.Can you make a sentence to _____ the meaning of the phrase?A. show outB. bring outC. turn outD. work out例题9.In a way I can see what you mean, even though I don’t ______ your point of view.A. recognizeB. shareC. agreeD. permit例题10.He is in______control of the company. I mean, the company is in_____control of him.A. the; /B. /; theC. the; theD. /; /例题11.If you think that treating a woman well means always_______her permission for things, think again.A. getsB. gotC. to getD. getting例题12.----Can you tell me what the word mean?------Why don't you________it up in a dictionary.A.pickB.takeC.lookD.make例题13.All possible means ________ been taken to prevent the river ________.A.have; pollutingB. has; pollutedC. has; from pollutedD. have; being polluted例题14.Jim went to answer the phone. _______, Harry started to prepare lunch.A. HoweverB. NeverthelessC. BesidesD. Meanwhile二.阅读理解解题技巧阅读理解例题1.The researchers’ report said, “While more notes are beneficial, if the notes are taken mindlessly, as is more likely the case on a laptop, the benefit disappears.”In another experiment aimed at testing long-term memory, students took notes as before but were tested a week after the lecture. This time, the students who wrote notesby hand performed significantly better on the exam.23.The author of the passage aims to .A.examine the importance of long-term memoryB.stress the benefit of taking notes by handC.explain the process of taking notesD.promote the use of laptops例题2.These two experiments suggest that handwritten notes are not only better for immediate learning and understanding, but that they also lead to superior revision in the future.24. The passage is likely to appear in __.A. a newspaper advertisementB. a computer textbookC. a science magazineD. a finance report例题3.Nitrogen(氮)and carbon are shared through miles of underground fungi(真菌)networks, making sure that all trees in the forest ecological system give and receive just the right amount to keep them all healthy. This hidden system works in a very similar way to the networks of neurons(神经元)in our brains, and when one tree is destroyed, it affects all.Simard talks about “mother trees”, usually the largest and oldest plants on which all other trees depend. She explains how dying trees pass on the wealth to the next generation, transporting important minerals to young trees so they may continue to grow. When humans cut down “mother trees” with no awareness of these highly complex “tree societies” or the networks on which they feed, we are reducing the chances of survival for the entire forest.30. “Mother trees” are extremely important because they .A.look the largest in size in the forestB.pass on nutrition to young treesC.seem more likely to be cut down by humansD.know more about the complex “tree societies”例题4.“We didn’t take any notice of it.” Simard says sadly. “Dying trees move nutrition into the young trees before dying, but we never give them chance.” If we could put across the message to the forestry industry, we could make a huge difference towards our environmental protection efforts for the future.31.The underlined word “it” in the last paragraph refers to .A.how “tree societies” workB.how trees grow oldC.how forestry industry developsD.how young trees survive32.What would be the best title for the passage?_____A.Old Trees Communicate Like HumansB.Young Trees Are In Need Of ProtectionC.Trees Are More Awesome Than You ThinkD.Trees Contribute To Our Society例题5.With around 100 students scheduled to be in that 9 am Monday morning lecture, it is no surprise that almost 20 people actually make it to the class and only 10 of them arestill awake after the first 10 minutes; it is not even a surprise that most of them are still in their pyjamas. Obviously, students are terrible at adjusting their sleep cycles to their daily schedule.43. What docs the author stress in Paragraph 1? ________A. Many students are absent from class.B. Students are very tired on Monday mornings.C. Students do not adjust their sleep patterns well.D. Students are not well prepared for class on Mondays.第7讲完型填空高中完型填空考察内容:1.完型填空高考话题:2010年:议论文2011年:经济类评论/议论2012年:新闻/人文类科技报道2013年:议论2014年:说明2.完型填空考查逻辑含义——需要用中文预判:例题:住的离公司近可以节约_______A.房租B.设施C.通讯D. 车费(2013闸北一模)Besides living near the work place is always welcome as it saves time and fares on __55__ .50.A.housing B. facilities munication D. transportation3.完型填空考查词汇:1)动词动词短语2)名词3)形容词4)副词5)独立的介词短语(2014年上海高考)52. A. occasionally B. habitually C. independently D. originally53. A. social B. political C. historical D. cultural56. A. confirms B. rejects C. outlines D. broadens57. A. for instance B. in addition C. on the contrary D. as a result58. A. motivation B. appearance C. emotion D. behaviour解题原则1.连词前后的对等关系:句子之间的关系不是并列就是转折:例题1.In spite of 40 winds and rough seas, Pickle made the voyage of more than 1, 000 miles in just over eight days....40.A.strong B.weak C.warm D.light例题2.The girl became increasingly worried about this, both when 46 and in her dreams.46. A. asleep B. away C. around D. awake完型选项的关系:例题3.David stepped out of the toilet and stopped in surprise —the library lights were off. The place was 29 . The doors had been shut.29.A.lonely B.empty C.noisy D.crowded例题4.She made it through the class.Perhaps she thanked the young man; she is not 51 .51.A.interested B.doubtful C.puzzled D.Sure例题5.It wasn’t hard;she 32 every minute of it.32.A.disliked B.loved C.expected D.bored例题6.“What’s up?”I asked.He answered in 47 English,“I…I no get money to buy book.”47.A.old B.broken C.traditional D.modern例题7.Is my main idea or purpose _clear_ throughout my draft? Do I ever lose sight of my purpose? Have I given my readers all of the _____ that is, facts, opinions, inferences --- that they need in order to understand my main idea? Finally, have I included too many _unnecessary_ details that may confuse readers? (上海卷)A. angles B . evidence C . information D . hints例题8.Eleven-year-old Angela had something wrong with her nervous system.She was unable to 36 .In fact,she could hardly make any 37 .36.A.see B.hear C.talk D.walk 37.A.progress B.difference C.movement D.achievement例题9.We can hate waiting, 38 it or even get good at it! But one thing is certain --- we cannot avoid it.38.A.accept B.control C.change D.improve例题10.As well, children arc even taught that hurting other players is _ acceptable or are pushed to continue playing even when they are injured. _59 , the media makes violence seem exciting. (上海卷)59. A. By contrast B. In additionC. As a resultD.After all例题11.Dr.Richardson never 33 her decision. 34 ,she was so pleased with May’s work that she later accepted two other deaf women as student nurses.33.A.regretted B.thought of C.liked D.believed34.A.In fact B.In a hurry C.In surprise D.In public例题12.Seeing that he had an 24 face, she let him in and gave him a nice treat. 24. A. interesting B. honest C. anxious D. angry例题13.When I took the first exam, I was shocked to find a 77, C-plus, on my test paper, 39 English was my best subject.39. A. but B. so C. for D. or例题14.I told her I would mess it up, 37 I had never worked at the bar before.37.A.because B.though C.until D.while例题15.The passengers on the bus watched with sympathy as Susan made her way carefully up the steps. She paid the driver and then, using her hands to the seats,settled in one of them. It had been a year since Susan became blind.A. touch B .grab C .count D .feel例题16.They continued to climb until they reached the old temple at the 49 of the mountain.49.A.tip B.back C.top D.bottom例题17.Children often do as much as what adults,particularly parents and teachers, expect of them.That is,tell a child he is “ 55 ,”and he may play the role of a foolish child.55.A.wise B.rude C.shy D.stupid例题18.I shrugged my shoulders.I thought my mother’s idea was a bad one,but I 43 .43.A.guessed B.obeyed C.begged D.admitted例题19.“What was he talking about!” Then I got it. I had set my trays on his wife’s orthopedic walker (助步器). I stood frozen as ice, but my face was 52 .52. A. cold B. full of joy C. pale D. on fire例题20.One day,Raul was miles away from the small ranch(牧场)house in a large valley.36 seemed to be all right,yet he felt strange and somewhat uneasy.36.A.Something B.Everything C.Anything D.Nothing例题21.44 he put on some warm clothes, it didn’t work, for there were too many of us.44. A. Since B. Once C. Whether D. Although例题22.Apparently, although no one wants to be 51 all the time, everyone needs some degree of privacy.51. A. noisy B. alone C. personal D. sociable例题23.Although she believed that she had a 38 chance of recovering,the doctors said that few ,if any,could come back to normal after getting this disease.。
一、填空题 (本大题满分48分) 本大题共有12题,只要求直接填写结果,每个空格填对得4分,否则一律得零分。
1.函数))((R x x f y ∈=图象恒过定点)1,0(,若)(x f y =存在反函数)(1x fy -=,则1)(1+=-x f y 的图象必过定点 。
2.已知集合{}R x y y A x∈-==,12,集合{}R x x x y y B ∈++-==,322,则集合{}B x A x x ∉∈且=。
3.若角α终边落在射线)0(043≤=-x y x 上,则=⎥⎦⎤⎢⎣⎡-+)22arccos(tan α 。
4.关于x 的方程)(01)2(2R m mi x i x ∈=+++-有一实根为n ,则=+nim 1。
5.数列{}n a 的首项为21=a ,且))((21211N n a a a a n n ∈+++=+ ,记n S 为数列{}n a 前n 项和,则n S = 。
6.(文)若y x ,满足⎪⎪⎩⎪⎪⎨⎧-≥-≤-≥+≤+1315y x y x y x y x ,则目标函数y x s 23-=取最大值时=x 。
(理)若)(13N n x x n∈⎪⎭⎫ ⎝⎛-的展开式中第3项为常数项,则展开式中二项式系数最大的是第 项。
7.已知函数)20,0)(2sin()(πϕϕ<<>+=A x A x f ,若对任意R x ∈有)125()(πf x f ≥成立,则方程0)(=x f 在[]π,0上的解为 。
8.某足球队共有11名主力队员和3名替补队员参加一场足球比赛,其中有2名主力和1名替补队员不慎误服违禁药物,依照比赛规定,比赛后必须随机抽取2名队员的尿样化验,则能查到服用违禁药物的主力队员的概率为 。
(结果用分数表示) 9.将最小正周期为2π的函数)2,0)(sin()cos()(πϕωϕωϕω<>+++=x x x g 的图象向左平移4π个单位,得到偶函数图象,则满足题意的ϕ的一个可能值为 。
杨浦新王牌xyA BCDO y x (7)设椭圆的方程为12222=+by a x )0(>>b a ,椭圆与y 轴正半轴的一个交点B 与两焦点21,F F 组成的三角形的 周长为324+,且3221π=∠BF F ,则此椭圆的方程为 (8)椭圆141622=+y x 上的点到直线022=-+y x 的最大距离是(9)椭圆14922=+y x 的焦点1F 、2F ,点P 为其上的动点,当∠1F P 2F 为钝角时,点P 横坐标的取值范围是 (10)若点P 是椭圆2219x y +=上的动点,定点A 的坐标为(2,0),则||PA 的取值范围是 (11)过点)0,2(-M 的直线m 与椭圆1222=+y x 交于21,P P ,线段21P P 的中点为P ,设直线m 的斜率为1k (01≠k ), 直线OP 的斜率为2k ,则21k k 的值为(12)如图,在平面直角坐标系xOy 中,椭圆12222=+by a x(0>>b a )被围于由4条直线a x ±=,b y ±=所围成的矩形ABCD 内,任取椭圆上一点P ,若OB n OA m OP ⋅+⋅= (m 、R n ∈),则m 、n 满足的一个等式是______________(11)如图,在直角坐标系xOy 中,设椭圆)0(1:2222>>=+b a by a x C 的左右两个焦点分别为21F F 、.过右焦点2F 且与x 轴垂直的直线l 与椭圆C 相交,其中一个交点为()1,2M . (1) 求椭圆C 的方程;(2) 设椭圆C 的一个顶点为),0(b B -,直线2BF 交椭圆C 于另一点N ,求△BN F 1的面积.(12)椭圆)0(1:2222>>=+b a by a x C 的左、右焦点分别是)0,(1c F -,)0,(2c F ,过1F 斜率为1的直线l 与椭圆C 相交于A ,B 两点,且2AF ,AB ,2BF 成等差数列.(1)求证:c b =;(2)设点)1,0(-P 在线段AB 的垂直平分线上,求椭圆C 的方程.。
第5节函数的单调性【重点知识梳理】一、函数的单调性1.函数的单调性是局部性质从定义上看,函数的单调性是指函数在定义域的某个子区间上的性质,是局部的特征.在某个区间上单调,在整个定义域上不一定单调.2.函数的单调区间的求法函数的单调区间是函数定义域的子区间,所以求解函数的单调区间,必须先求出函数的定义域.对于基本初等函数的单调区间可以直接利用已知结论求解,如二次函数、对数函数、指数函数等;如果是复合函数,应根据复合函数的单调性的判断方法,首先判断两个简单函数的单调性,再根据“同则增,异则减”的法则求解函数的单调区间.【注意】单调区间只能用区间表示,不能用集合或不等式表示;如有多个单调区间应分别写,不能用并集符号“∪”联结,也不能用“或”联结.二、函数单调性的判断对于给出具体解析式的函数,证明其在某区间上的单调性有两种方法:(1)结合定义(基本步骤为取值、作差或作商、变形、判断)证明;(2)可导函数则可以利用导数证明.对于抽象函数单调性的证明,一般采用定义法进行.例1.判断函数g (x )=-2x x -1在 (1,+∞)上的单调性.三、求函数的单调区间的常用方法(1)利用已知函数的单调性,即转化为已知函数的和、差或复合函数,求单调区间.(2)定义法:先求定义域,再利用单调性定义.(3)图象法:如果f (x )是以图象形式给出的,或者f (x )的图象易作出,可由图象的直观性写出它的单调区间.(4)导数法:利用导数的正负确定函数的单调区间.例2.函数f (x )=|x -2|x 的单调减区间是( ) A .[1,2]B .[-1,0]C .[0,2]D .[2,+∞)四、单调性的应用主要涉及利用单调性求最值,进行大小比较,解抽象函数不等式,解题时要注意:一是函数定义域的限制;二是函数单调性的判定;三是等价转化思想与数形结合思想的运用.例3.(1)函数f (x )=1x -1在[2,3]上的最小值为________,最大值为________. (2)已知函数f (x )=1a -1x(a >0,x >0),若f (x )在⎣⎡⎦⎤12,2上的值域为⎣⎡⎦⎤12,2,则a =__________.【高频考点突破】考点一 函数单调性的判断及应用例1 讨论f (x )=a x +a -x (a >0,且a ≠1)在(0,+∞)上的单调性.【变式探究】证明函数f (x )=2x -1x在(-∞,0)上是增函数.考点二 求函数的单调区间例2、求出下列函数的单调区间:(1)f (x )=|x 2-4x +3|;(2)f (x )=log 2(x 2-1).【变式探究1】设函数y =f (x )在(-∞,+∞)内有定义.对于给定的正数k ,定义函数f k (x )=⎩⎪⎨⎪⎧ f x ,f x ≤k ,k ,f x >k ,取函数f (x )=2-|x |.当k =12时,函数f k (x )的单调递增区间为( )A .(-∞,0)B .(0,+∞)C .(-∞,-1)D .(1,+∞)【变式探究2】(1)给定函数①y =x ;②y =log 0.5(x +1);③y =|x -1|;④y =2x +1.其中在区间(0,1)上单调递减的函数序号是________.(2) 若函数f (x )=|2x +a |的单调递增区间是[3,+∞),则a =________.考点三 抽象函数的单调性例3 定义在R 上的函数y =f (x ),f (0)≠0,当x >0时,f (x )>1,且对任意的a ,b ∈R ,有f (a +b )=f (a )·f (b ).(1)证明:f (0)=1;(2)证明:对任意的x ∈R ,恒有f (x )>0;(3)证明:f (x )是R 上的增函数;(4)若f (x )·f (2x -x 2)>1,求x 的取值范围.考点四 利用单调性求函数的最值例4、函数f (x )=2x -a x的定义域为(0,1](a 为实数). (1)当a =-1时,求函数y =f (x )的值域;(2)若函数y =f (x )在定义域上是减函数,求a 的取值范围;(3)求函数y =f (x )在(0,1]上的最大值及最小值,并求出函数取最值时x 的值.考点五 函数中的新定义问题例5、函数f (x )的定义域为A ,若x 1,x 2∈A 且f (x 1)=f (x 2)时总有x 1=x 2,则称f (x )为单函数,例如,函数f (x )=2x +1(x ∈R)是单函数.下列命题:①函数f(x)=x2(x∈R)是单函数;②指数函数f(x)=2x(x∈R)是单函数;③若f(x)为单函数,x1,x2∈A且x1≠x2,则f(x1)≠f(x2);④在定义域上具有单调性的函数一定是单函数.其中的真命题是________.(写出所有真命题的编号)【变式探究】(1)定义新运算“⊕”:当a≥b时,a⊕b=a;当a<b时,a⊕b=b2,则函数f(x)=(1⊕x)x-(2⊕x),x∈[-2,2]的最大值等于()A.-1 B.1 C.6 D.12(2)设f(x)与g(x)是定义在同一区间[a,b]上的两个函数,若对任意x∈[a,b],都有|f(x)-g(x)|≤1成立,则称f(x)和g(x)在[a,b]上是“亲密函数”,区间[a,b]称为“亲密区间”.若f(x)=x2+x+2与g(x)=2x+1在[a,b]上是“亲密函数”,则其“亲密区间”可以是() A.[0,2] B.[0,1] C.[1,2] D.[-1,0]【当堂巩固】1.定义在R上的偶函数y=f(x)满足f(x+1)=-f(x),且在[-1,0]上单调递增,设a=f(3), b=f(2), c=f(2),则a、b、c的大小关系是。
【课后作业】
【题目1】过点)5,3(P 且与)2,4(=d 平行的直线l 的点方向式方程为。
【题目2】求过点()2,1-M ,且与两坐标轴围成等腰直角三角形的直线l 的点方向式方程。
【题目3】求过点()2,5A -,且平行于直线:4390l x y --=的直线方程。
【题目4】求经过点()3,4P -,且横、纵截距相等的直线方程。
【题目5】过点()3,0,倾斜角为
3
π的直线方程为。
【题目6】m 为任意实数,直线()()1215m x m y m -+-=-必过一定点,则此定点坐标为( )A 、()9,4 B 、()9,4- C 、()4,9 D 、()4,9-
【题目7】过点()1,4P 的直线在两个坐标轴上的截距都为正,且截距之和最小,则直线方程为( )
A 、260x y +-=
B 、260x y +-=
C 、260x y -+=
D 、260x y --=
【题目8】已知()()3,2,1,4A B --,则线段AB 的垂直平分线方程是。
【题目9】(1)垂直于x 轴的直线不能用直线的点方向式表示
(2)垂直于x 轴的直线不能用直线的点法向式表示
(3)垂直于x 轴的直线不能用直线的一般式表示
(4)垂直于x 轴的直线不能用直线的点斜式表示
命题中真命题的个数为:( )
(A )0 (B )1(C )2 (D )3
【题目10】若将直线033=+-y x 绕着点()0,3-P 按逆时针方向旋转︒90,则旋转后所得的直线方程是 ( ) (A) 0333=++y x (B) 0333=+-y x (C) 0333=-+y x (D) 0333=--y x
【题目11】若直线1l :()032=++-ay x a 和2l :03=--ay x ,则“1=a ”是“1l 的法向量恰是2l 的方向向量”的 ( )
(A ) 充分非必要条件 (B )必要非充分条件
(C )充分必要条件 (D )既非充分又非必要条件
【题目12】直线m y m x m 2)2()2(=-++在x 轴上的截距为3,则m 的值为 ( )(A)
5
6、6 (B)56- (C)-6 ;56- (D)-6
【题目13】直线)0,0(0><=++ac ab c by ax 不经过 ( )
(A)第一象限 (B)第二象限 (C)第三象限 (D)第四象限
【课堂小结】
1.直线方程有五种形式,这五种形式的方程表示的直线各有适用范围,解题时应注意不要丢解;含参数的直线方程问题用数形结合法常常简捷些。
2.求直线的方程通用的解决方法是待定系数法;根据所知条件选择恰当的直线方程的形式是解题的关键。