2019數(shù)學(xué)人教a版選修11優(yōu)化練習(xí)12充分條件與必要條件版含解析

[課時(shí)作業(yè)][A組基礎(chǔ)穩(wěn)固]a)1．設(shè)a，b∈R，那么“>1”是“a>b>0”的(bA．充分不用要條件B．必需不充分條件C．充分必需條件D．既不充分也不用要條件aaa－bb>0b<0分析：由>1得，－1＝>0，即b(a－b)>0，得或，即a>b>0bbba>ba<ba或a<b<0，所以“>1”是“a>b>0”的必需不充分條件，選B.b答案：Bπ1)2．“θ≠”是“cosθ≠”的(32A．充分不用要條件B．必需不充分條件C．充分必需條件D．既不充分也不用要條件π11π分析：因?yàn)椤唉取?”是“cosθ≠”的逆否命題：“cosθ＝”是“θ＝”的必223要不充分條件，選B.答案：Ba－1>0；命題q：y＝ax是R上的增函數(shù)，則p是q建立的( )3．命題p：aA．必需不充分條件B．充分不用要條件C．充分必需條件D．既不充分也不用要條件a－1分析：由>0得a>1或a<0；由y＝ax是R上的增函數(shù)得a>1.所以，p是qa建立的必需不充分條件，選A.答案：A4．對(duì)于非零向量有a＝(a1，a2)和b＝(b1，b2)，“a∥b”是“a1b2－a2b1＝0”的( )A．必需不充分條件B．充分必需條件C．充分不用要條件D．既不充分也不用要條件分析：由向量平行的坐標(biāo)表示可得a∥b?a1b2－a2b1＝0，選B.答案：B5．已知h＞0，設(shè)命題甲為：兩個(gè)實(shí)數(shù)a、b知足|a－b|＜2h，命題乙為：兩個(gè)實(shí)數(shù)a、b知足|a－1|＜h且|b－1|＜h，那么( )A．甲是乙的充分但不用要條件B．甲是乙的必需但不充分條件C．甲是乙的充分必需條件D．甲既不是乙的充分條件也不是乙的必需條件|a－1|＜h，－h(huán)＜a－1＜h，分析：因?yàn)樗詜b－1|＜h，－h(huán)＜b－1＜h，兩式相減得－2h＜a－b＜2h，故|a－b|＜2h.即由命題乙建立推出命題甲建立，所以甲是乙的必需條件．|a－2|＜h，因?yàn)橥硪部傻脇a－b|＜2h.|b－2|＜h，所以，命題甲建立不可以確立數(shù)題乙必定建立，所以甲不是乙的充分條件，故應(yīng)選B.答案：B6．已知各個(gè)命題A、B、C、D，若A是B的充分不用要條件，C是B的必需不充分條件，D是C的充分必需條件，試問(wèn)D是A的________條件(填：“充分不必需”“必需不充分”“充分必需”“既不充分也不用要”)．分析：∵A?B?C?D，∴D是A的必需不充分條件．答案：必需不充分7．在平面直角坐標(biāo)系xOy中，直線x＋(m＋1)y＝2－m與直線mx＋2y＝－8相互垂直的充分必需條件是m＝________.分析：x＋(m＋1)y＝2－m與mx＋2y＝－8相互垂直?1·m＋(m＋1)·2＝0?m＝2.32答案：－38．有四個(gè)命題：①“x2≠1”是“x≠1”的必需條件；②“x＞5”是“x＞4”的充分不用要條件；③“xyz＝0”是“x＝0，且y＝0，且z＝0”的充分必需條件；④“x2＜4”是“x＜2”的充分不用要條件．此中是假命題的有________．分析：“x2≠1”是“x≠1”的充分條件，①錯(cuò)誤；“x＞5”是“x＞4”的充分不用要條件，②正確；“xyz＝0”是“x＝0，且y＝0，且z＝0”的必需不充分條件，③錯(cuò)誤；“x2＜4”是“x＜2”的充分不用要條件，④正確．答案：①③9．在以下各題中，判斷A是B的什么條件，并說(shuō)明原因．(1)A：|p|≥2，p∈R，B：方程x2＋px＋p＋3＝0有實(shí)根；(2)A：圓x2＋y2＝r2與直線ax＋by＋c＝0相切，B：c2＝(a2＋b2)r2.分析：(1)當(dāng)|p|≥2時(shí)，比如p＝3，則方程x2＋3x＋6＝0無(wú)實(shí)根，而方程x2＋px＋p＋3＝0要有實(shí)根，必有p≤－2或p≥6，可推出|p|≥2，故A是B的必需不充分條件．(2)若圓x2＋y2＝r2與直線ax＋by＋c＝0相切，圓心到直線ax＋by＋c＝0的距離等于r，即r＝|c|，所以c2＝(a2＋b2)r2；a2＋b2反過(guò)來(lái)，若c2＝(a2＋b2)r2，則|c|＝r建立，a2＋b2說(shuō)明x2＋y2＝r2的圓心(0,0)到直線ax＋by＋c＝0的距離等于r，即圓x2＋y2＝r2與直線ax＋by＋c＝0相切，故A是B的充分必需條件．10．已知x，y都是非零實(shí)數(shù)，且x>y，求證：11x<的充分必需條件是xy>0.y1111y－x<0.證明：(1)必需性：由<，得－<0，即xyxyxy又由x>y，得y－x<0，所以xy>0.(2)充分性：由xy>0，及x>y，得xy11>，即<.xyxyxy11綜上所述，<的充分必需條件是xy>0.xy[B組能力提高]1．(2016·高考北京卷)設(shè)a，b是向量，則“|a|＝|b|”是“|a＋b|＝|a－b|”的( )A．充分不用要條件B．必需不充分條件C．充分必需條件D．既不充分也不用要條件分析：聯(lián)合平面向量的幾何意義進(jìn)行判斷．若|a|＝|b|建立，則以a，b為鄰邊的平行四邊形為菱形．a(chǎn)＋b，a－b表示的是該菱形的對(duì)角線，而菱形的兩條對(duì)角線長(zhǎng)度不必定相等，所以|a＋b|＝|a－b|不必定建立，進(jìn)而不是充分條件；反之，若|a＋b|＝|a－b|成立，則以a，b為鄰邊的平行四邊形為矩形，而矩形的鄰邊長(zhǎng)度不必定相等，所以|a|＝|b|不必定建立，進(jìn)而不是必需條件．故“|a|＝|b|”是“|a＋b|＝|a－b|”的既不充分也不用要條件．答案：D2．不等式x－1>0建立的充分不用要條件是( )A．－1<x<0或x>1B．0<x<1C．x>1D．x>2分析：由不等式知x>1為x－1>0的充分必需條件，聯(lián)合選項(xiàng)知D為充分不用要條件．答案：D3．“a＝1”是“直線x＋y＝0和直線x－ay＝0相互垂直”的________條件．分析：由1×1＋1×(－a)＝0，∴a＝1，即為充分必需條件．答案：充分必需4．函數(shù)y＝x2＋bx＋c(x∈[0，＋∞))是單一函數(shù)的充分必需條件是________．分析：若b≥0，函數(shù)y＝x2＋bx＋c在[0，＋∞)上是單一增添的；若y＝x2＋bx＋c在[0，＋∞)上是單一的，則只好是單一增添的，故b≥0.答案：b≥05．已知p：－4<x－a<4，q：(x－2)(x－3)<0，且q是p的充分條件，求a的取值范圍．分析：設(shè)q、p表示的范圍為會(huì)合A、B，則A＝(2,3)，B＝(a－4，a＋4)．因q是p的充分條件，則有A?B，a－4≤2，即所以－1≤a≤6.a＋4≥3.6．(1)能否存在實(shí)數(shù)p，使“4x＋p<0”是“x2－x－2>0”的充分條件？假如存在，求出p的取值范圍；(2)能否存在實(shí)數(shù)p，使“4x＋p<0”是“x2－x－2>0”的必需條件？假如存在，求出p的取值范圍．p分析：令會(huì)合M＝{x|4x＋p<0}＝{x|x<－}，4N＝{x|x2－x－2>0}＝{x|x<－1或x>2}．p(1)若M?N，則－≤－1?p≥4，4所以p≥4時(shí)，“4x＋p<0”是“x2－x－2>0”的充分條件；(2)若“4x＋p<0”是“x2－x－2>0”的必需條件，則M?N，p明顯{x|x<－}?{x|x<－1或x>2}不建立．4所以不存在實(shí)數(shù)p，使“4x＋p<0”是“x2－x－2>0”的必需條件．Unit12FourseasonsinonedayPartOne要點(diǎn)解說(shuō)一、要點(diǎn)單詞、詞組快速地_______走開_______轉(zhuǎn)變________(陽(yáng)光）照射___________季節(jié)________親愛(ài)的________報(bào)告__________溫度_______度________以前________在外面________改變________雨傘_______達(dá)成______走路__________真切的______穿上________午飯時(shí)刻________劇烈地；努力地______你的；你們的______我的第一天________________一些風(fēng)趣的東西________________好多衣服________________開始照射________________在午飯時(shí)間________________下大雨________________在某一天________________二、要點(diǎn)語(yǔ)法TodayismyfirstdayinLondonandIlearnedsomethinginterestingabouttheweatherhere.1）At,in跟地址的差異：at+小地址in+大地址________home________school________Guangzhou________shop________England________China________museum________Beijing________theplayground2)somethinginteresting一些風(fēng)趣的東西something跟形容詞連用時(shí)，形容詞要后置。一些冷的東西_________________一些新的東西_________________一些可怕的東西_________________一些無(wú)聊的東西_________________What’sthetemperature?Theweatherreportsaidthetemperaturewasonly15℃.What’sthetemperature?這是問(wèn)答氣溫的常用句型?；卮饡r(shí)，一般要用It’s+數(shù)字+單位。同時(shí)，我們也能夠用Howmanydegrees?來(lái)咨詢溫度。依據(jù)實(shí)質(zhì)狀況回答以下問(wèn)題。What’sthetemperaturenow?_____________________________________________Whatwasthetemperatureyesterday?_____________________________________________Whatwasthetemperaturethedaybeforeyesterday?_____________________________________________IputonlotsofclothesbeforeIwenttomynewschool.1).before以前對(duì)應(yīng)詞：after以后晚餐前，你能夠看一會(huì)兒電視。_____________________________________________放學(xué)后，他往常跑步。___________________________________________________2).puton穿上Putonyourcoat.穿上你的大衣。注意：puton重申穿上的動(dòng)作，而wear重申衣著的狀態(tài)。用puton,wear的正確形式填空1.MrWang,ourEnglishteacher,oftenapairofdarkglasses(墨鏡).2.TheboyayellowT-shirtcomesfromAmerica.3.yourjacket,Lucy.It’scoldoutside.4.thenewskirt.Ihadnoumbrella.Therewasnorain.Therewas/wereno可用來(lái)描繪過(guò)去某處沒(méi)有某人某物。No后邊能夠直接加名詞。我們周末不用上學(xué)。_____________________________________________天空沒(méi)有云朵。_____________________________________________我沒(méi)有故事書。_____________________________________________Butwhenschoolfinishedat3p.m.注意表示時(shí)間的介詞搭配：in和‘‘年、季節(jié)、月’’搭配；on和禮拜、日期以及‘‘有day的節(jié)日’’搭配；3.at和‘‘點(diǎn)鐘及沒(méi)有day的節(jié)日’’搭配。________10:00a.m.________noon________Sunday________night________SpringFestival________October12th________Sundaymorning________autumn________themorning________themorningofOct.12th________October________2014________acoldmorning________theafternoon________Mid-autumnDayIputonmycoatandwalkedhome.walkto+地址步行到某處，但當(dāng)后邊的地址是home，here,there時(shí)，介詞to省略。步行回家_______________回家_______________來(lái)這邊_______________去那處_______________PartTwo講堂練習(xí)一、用動(dòng)詞的正確形式填空TomandMary___________(come)toChinalastmonth.Mike_________________(notgo)tobeduntil12o'clocklastnight.Sohe______(get)uplate.Mary__________(read)Englishyesterdaymorning.Tom___________(begin)tolearnChineselastyear.Mymother________________(notdo)houseworkyesterday.There____________atelephonecallforyoujustnow.(be)7.-When_______you_________(come)tochina?-Lastyear.8._________(be)itcoldinyourcityyesterday?Howmanypeople________(be)thereinyourclasslastterm?There________(be)afootballmatchonTVyesterdayevening,butI_________(have)notimetowatchit.二、依據(jù)例子改句例：Ihadlunchat12o’clockyesterday.否認(rèn)句：Ididn’thavelunchat12o’clockyesterday.一般疑問(wèn)句：Didyouhavelunchat12o’clock?必定/否認(rèn)回答：Yes,Idid.No,Ididn’t.對(duì)劃線部分發(fā)問(wèn)：Whatdidyoudoat12o’clockyesterday.1.Thechildrenhadagoodtimeinthepark.否認(rèn)句：__________________________________________一般疑問(wèn)句：________________________________________必定/否認(rèn)回答：____________________________________對(duì)劃線部分發(fā)問(wèn)：____________________________________2.Therewereaboutninehundredpeopleattheconcert.否認(rèn)句：__________________________________________一般疑問(wèn)句：________________________________________必定/否認(rèn)回答：____________________________________3.Anndidherhomeworkyesterdayevening.否認(rèn)句：__________________________________________一般疑問(wèn)句：________________________________________對(duì)劃線部分發(fā)問(wèn)：____________________________________4.LastweekIreadanEnglishbook.否認(rèn)句：__________________________________________一般疑問(wèn)句：________________________________________必定/否認(rèn)回答：____________________________________對(duì)劃線部分發(fā)問(wèn)：____________________________________5.Mybrotherwasintheparkjustnow.否認(rèn)句：__________________________________________一般疑問(wèn)句：________________________________________對(duì)劃線部分發(fā)問(wèn)：____________________________________PartThree課后練習(xí)一、依據(jù)中文并使用相應(yīng)形式填空1.The__________(氣溫)fallsbelowzeroatnight.2.Doyoulistentotheweather__________(報(bào)告)everyday?It’sraining_______(劇烈地).Ihaveno________(雨傘).Wehavealotof__________(陽(yáng)光)hereinsummer.It's__________（多云的）today.二、選擇題。()1.______theweatherliketoday?A.WhatB.HowC.What’s()2.Look,it’s_____.Butyesterdayit______sunny.A.rains,isB.raining,wasC.raining,is( )3.Myfather＿＿＿＿＿＿illyesterday．A.isn'tB.aren'tC.wasn't()4._____isthebesttime_____makeasnowman.A.Autumn,toB.Winter,toC.Winter,for()5.Itisvery____inOctober,soyoucanwearashirt.A.coldB.hotC.cool()6.—WhowasondutylastFriday﹖—＿＿＿＿＿＿．A.IamB.IwasC.No,Iwasn't()7.____he____footballtwodaysago?A.Does,playB.Did,playedC.Did,play()8.It’sa______morning.A.sunB.sunyC.sunny()9.Inautumn,it’scoolandwindy.So,wecan_______.A.flyingkitesB.flykitesC.flieskites()10.HowcanIgohome_______school?A.afterB.duringC.at三、使用適合的詞組填空我過(guò)了一個(gè)繁忙的周末。I______________________________________weekend.Jenny喜愛(ài)看書。昨晚她看了一本英語(yǔ)書。Jennylikes___________________.She_________anEnglishbooklastnight.今日是我在中國(guó)的第一天。Todaywas_________________________inChina.我認(rèn)識(shí)到了對(duì)于英國(guó)的一些風(fēng)趣的事情。Ilearned_________＿＿＿＿＿aboutEngland.我穿上大衣走路回家去了。I_______________mycoatandwalkedhome.四、改錯(cuò)題1．HowisJaneyesterday?_____________________2．Hegotoschoolbybuslastweek.____________________________3．Heoftengoeshomeat6:00lastmonth.____________________________4．Icanflykitessevenyearsago.______________________________5．Didyousawhimjustnow.____________________________________6．Tomwasn’twatchTVlastnight.____________________________________7．Ididn’tmyhomeworkyesterday.____________________________________8．Hewaitforyouthreehoursago.____________________________________9．Whofinditjustnow?________________________________________10.Whatmakehimcryjustnow?________________________________五、依據(jù)實(shí)質(zhì)狀況回答以下問(wèn)題。What’stheweatherlikeinGuangzhounow?______________________________________________________________________What’syourfavouriteseason?______________________________________________________________________Whatistheweatherlikeinspring?_______________________________________________________________________Doyoulikewinter?Why?_______________________________________________________________________Isitasunnyday?_______________________________________________________________________Whichseasondoyoulikebest?_______________________________________________________________________六、完形填空。InEnglandwinterisnotverycoldandsummerisnotveryhot.There1agreatdifferencebetweensummerandwinter.Whyisthis?Englandhasawarmwinteranda2summerbecauseitisanislandcountry.Inwintertheseais3thantheland.Thewindsfromtheseacarrieswarmair4England.Insummertheseaiscoolerthantheland.ThewindsfromtheseabringcoolairtoEngland.The5windsblow(吹)overEnglandalltheyearround.Theyblowfromthesouthwest(西南).Theyare6winds.Theybring7toEnglandEnglandis8thantheeast.Morerainfallsthere.Thefourseasonsareall9monthslong.IfyouwanttovisitEngland,youcangotherein10.()1.A.isn'tB.doesn'thaveC.isD.has(B.coolC.hotD.warm(B.warmC.hotD.hotter(B.fromC.forD.of(B.eastC.southeastD.southwest(B.winterC.wetD.cold(B.rainC.coldD.snow(B.drierC.wetterD.colder(B.fourC.threeD.sameC.winterD.eachseason七、閱讀理解。Therearefourseasonsinayear:spring,summer,autumnandwinter.Eachseasonhasthreemonths.Springisthefirstseasonoftheyear.Inthispartoftheworld,thespringmonthsareMarch,AprilandMay.Inspring,theweathergetswarmerandthefieldsturngreen.Thisisabusytimeforthepeasants.months,theplantsandflowersareattheirbest.Nextcometheautumnmonths:September,OctoberandNovember.Autumnharvestandthepeasantsareverybusy.Winteristhelastseasonoftheyear.December,JanuaryandFebmaryarethewintermonths,itiscoldinwinter.Year'sDay,wewisheachotherahappyNewYear.()1.Howmanyseasoninayear?Eachseasonhas______months.A.Four;fourB.Four;threeC.Four;fiveD.Three;four()2.Whatistheweatherlikeinspring?A.HotB.WarmC.CoolD.Cold()3.__________theplantsandflowersareattheirbest.A.DuringthewinterB.DuringthespringC.DuringtheautumnD.Duringthesummer()4.Autumnbeginsin__________.A.JuneB.SeptemberC.JulyD.Octomber()5.Autumnisbesttimefor_______.A.plantingB.growingC.snowingD.harvest八、寫作：Whichseasondoyoulikebest?Why?__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________21.1第2課時(shí)二次根式的性質(zhì)知識(shí)點(diǎn)1二次根式的非負(fù)性1．若x－1＋(y＋2)2＝0，則(x＋y)2018＝( )A．－1B．1C．32018D．－320182．若|x－y|＋y－2＝0，則xy－3的值為________．知識(shí)點(diǎn)2二次根式的性質(zhì)(a)2＝a(a≥0)3．計(jì)算(15)2的結(jié)果是( )[^#*%~]A．225B．15C．±15D．－1514．把4寫成一個(gè)正數(shù)的平方的形式是()[#@^*~]41B．(17A．(2)2)2241D．(±17)2C．(±2)2425．計(jì)算：(1)(11)2；(2)(－20)2.[#@^~%][@#*%^]知識(shí)點(diǎn)3二次根式的性質(zhì)a2＝|a|6．計(jì)算：（－2）2＝|________|＝________．7．以下計(jì)算正確的選項(xiàng)是( )A．(5)2＝25B．(－3)2＝3C.（－3）2＝－3D.02＝08．計(jì)算：9(1)；(2)（－7）2.16[#*^~%][^#%~*]9．若x－2＋3＋y＝0，則(x＋y)2019的值為( )[*~%&^]A．5B．－5C．1D．－110．若（x－3）2＝3－x，則x的取值范圍是________．11．［教材習(xí)題第2題變式］計(jì)算：222(1)3＋－；3（a＋3）2－a2(a>0)．[^#*%@][#*^~%][%^#&*]12．閱讀資料，解答問(wèn)題．[~%*@^]例：若代數(shù)式（2－a）2＋（a－4）2的值是常數(shù)2，求a的取值范圍．剖析：原式＝|a－2|＋|a－4|，因?yàn)閨a－2|表示數(shù)a在數(shù)軸上對(duì)應(yīng)的點(diǎn)到數(shù)2在數(shù)軸上對(duì)應(yīng)的點(diǎn)的距離，|a－4|表示數(shù)a在數(shù)軸上對(duì)應(yīng)的點(diǎn)到數(shù)4在數(shù)軸上對(duì)應(yīng)的點(diǎn)的距離，所以我們能夠借助數(shù)軸進(jìn)行剖析．[~@^%*]圖21－1－1解：原式＝|a－2|＋|a－4|.在數(shù)軸上看，應(yīng)分三種狀況議論：[%#&^*]①當(dāng)a＜2時(shí)，原式＝2－a＋4－a＝6－2a；[#@~%*]②當(dāng)2≤a≤4時(shí)，原式＝a－2＋4－a＝2；③當(dāng)a＞4時(shí)，原式＝a－2＋a－4＝2a－6.經(jīng)過(guò)剖析可得a的取值范圍是2≤a≤4.(1)此例題的解答過(guò)程頂用了哪些數(shù)學(xué)思想？(2)化簡(jiǎn)：（3－a）2＋（a－7）2.1．B則原式＝(－1)2018＝1.[*&@#~]12.23．B4．B5．(1)11(2)206.－227.D[~%*&#]38．(1)(2)749．D10．x≤3[@%&*^]2211．解：(1)原式＝3＋＝3.[*#^~%]3(2)原式＝a＋3－a＝3.12．解：(1)數(shù)形聯(lián)合思想，分類議論思想．(2)原式＝|3－a|＋|a－7|.[%^@*&]①當(dāng)

a＜3

時(shí)，原式＝

3－a＋7－a＝10－2a；

[#&^@%]②當(dāng)

3≤a≤7

時(shí)，原式＝

a－3＋7－a＝4；③當(dāng)

a＞7

時(shí)，原式＝

a－3＋a－7＝2a－10.2．1有理數(shù)的加法(第1課時(shí))1．同號(hào)兩數(shù)相加，取與____________同樣的符號(hào)，并把____________相加．2．異號(hào)兩數(shù)相加，取絕對(duì)值____________的加數(shù)的符號(hào)，并用較大的絕對(duì)值____________較小的絕對(duì)值．3．互為相反數(shù)的兩個(gè)數(shù)相加得____________；一個(gè)數(shù)同零相加，仍得____________．A組基礎(chǔ)訓(xùn)練1．計(jì)算－2＋1的結(jié)果是()A．1B．－1C．3D．－32．兩個(gè)有理數(shù)的和等于零，則這兩個(gè)有理數(shù)( )A．都是零B．一正一負(fù)C．有一個(gè)加數(shù)是零D．互為相反數(shù)3．以下運(yùn)算中，正確的個(gè)數(shù)有( )(－5)＋5＝0②(－10)＋(＋7)＝－3③3＋(－4)＝－7④(－3)＋2＝1⑤(－1)＋(＋2)＝－1A．1B．2C．3D．44．一個(gè)數(shù)是－4，另一個(gè)數(shù)比它大2，則另一個(gè)數(shù)是()A．－2B．－6C．2D．65．假如兩個(gè)數(shù)的和是負(fù)數(shù)，那么( )A．這兩個(gè)加數(shù)都是負(fù)數(shù)B．一個(gè)加數(shù)為負(fù)，另一個(gè)加數(shù)為0C．兩個(gè)加數(shù)異號(hào)，且負(fù)數(shù)的絕對(duì)值大D．必屬于以上三種狀況之一6．計(jì)算：(1)(－4)＋(＋2)＝____________；11(2)(－)＋(－)＝____________；2321(3)1＋(－10)＝____________.337．比較以下各式的大小，用”＞”、”＜”或”＝”連結(jié)．(－8)＋(＋8)____________0；(－8)＋(－8)____________0；5＋＋____________0；0＋(－4)__