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抛物线y=ax2+bx+c(对称轴为x=1)的图象如图所示,下列四个判断中正确的是( )
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如图所示已知抛物线与x轴交于A-10与y轴交于点C03且对称轴为直线x=1 求抛物线的
如图①已知抛物线y=ax2+bx+c经过点A03B30C43.1求抛物线的函数表达式2求抛物线的顶点
已知抛物线y=ax2+bx+c的对称轴是经过点20且与y轴平行的直线抛物线与x轴相交于点A10与y轴
如图所示已知二次函数y=ax2+bx+c的图象与x轴交于
B.两点,与y轴交于点C.对称轴为直线x=1.直线y=﹣x+c与抛物线y=ax
2
+bx+c交于C.D.两点,D.点在x轴下方且横坐标小于3,则下列结论: ①2a+b+c>0; ②a﹣b+c<0; ③x(ax+b)≤a+b; ④a<﹣1. 其中正确的有( )
A.4个
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函数y=mx2的图象如图所示则m0在对称轴左侧y随x的增大而在对称轴右侧y随x的增大而增大顶点坐标是
若所求的二次函数图象与抛物线y=2x2-4x-1有相同的顶点并且在对称轴的左侧y随x的增大而增大在对
)y=-x
2
+2x+4 (
)y=-ax
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-2ax-3(a>0) (
)y=-2x
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-4x-5 (
)y=ax
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-2ax+a-3(a<0)
如图抛物线y=ax2+bx过点B.1﹣3对称轴是直线x=2且抛物线与x轴的正半轴交于点A.1求抛物线
已知抛物线的对称轴是经过点20且与y轴平行的直线抛物线与x轴相交于点A.10与y轴相交于点B.03其
已知抛物线y=ax2+bx+c的对称轴是经过点20且与y轴平行的直线抛物线与x轴相交于点A10与y
已知二次函数y=ax2+bx+ca≠0的图象如图所示则下列说法①c=0②该抛物线的对称轴是直线x=-
1
2
3
4
如图1已知二次函数y=ax2﹣8ax+12a>0的图象与x轴分别交于A.B.两点与y轴交于点C.点P
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如图1已知二次函数y=ax2﹣8ax+12a>0的图象与x轴分别交于A.B.两点与y轴交于点C.点P
若一次函数y=ax+ba≠0的图象与x轴的交点坐标为-20则抛物线y=ax2+b的对称轴为
)直线x=1 (
)直线x=-2 (
)直线x=-1 (
)直线x=-4
若一次函数y=ax+ba≠0的图象与x轴的交点坐标为-20则抛物线y=ax2+bx的对称轴为
直线x=1
直线x=-2
直线x=-1
直线x=-4
抛物线y=ax2+bx+c的对称轴为直线x=﹣1部分图象如图所示下列判断中①abc>0②b2﹣4ac
2
3
4
5
二次函数y=ax2+bx+c的图象与x轴相交于-10和50两点则该抛物线的对称轴是.
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WhenOliverSacks82diedonAug30athishomeinNewYorkCitytheworldwassaddenedbythelossofabrilliantneurologist神经学者andatrulybeautifulmind. London﹣bornSackswasmostfamousforhiswriting.AForbesobituary讣告callshimoneofthegreatestwritersofscienceofthepast50years.Maybethegreatest. Inhisbest﹣selling1985bookTheManWhoMistookHisWifeforaHatSacksdescribedamanwhocouldnottellthedifferencebetweenhiswife'sfaceandhishatbecausehisbrainhaddifficultytellingwhathesaw. In2006Discovermagazinerankeditamongthe25greatestsciencebooksofalltimedeclaringLotsofneuroscientistsnowlookingintothemysteriesofthehumanbraincite列举thisbookastheirgreatestinspiration/ His1973bookAwakeningsisaboutagroupofpatientswhowerefrozeninadecades﹣longsleepuntilSackstriedanewtreatment.Thebookledtoa1990movieinwhichSackswasactedbyRobinWilliams.Itwasnominated提名forthreeAcademyAwards. AnotherbookAnAnthropologistonMarspublishedin1995describedcaseslikethatofapainterwholosthiscolorvisioninacaraccidentbutfoundnewcreativepowerinblack﹣and﹣whiteimages.Sacksalsowrotethestoryofa50﹣year﹣oldmanwhosuddenlyregainedsightafternearlyalifetimeofblindness.Theexperiencewasadisaster.Theman'sbraincouldnotmakesenseofthevisualworld.Afterafullandrichlifeasablindpersonhebecameaverydisabledandmiserable悲惨的sightedmanSackswrote.Whenhewentblindagainhewasrathergladofit. DespitethedramaandunusualstoriesSacks'bookswerenotmeanttobefreakshows.OliverSackshumanizesillness…hewritesofbodyandmindandfromeveryoneofhiscasestudiesthereshowsafeelingofrespectforthepatientandfortheillnessRoaldHoffmannaNobelPrize﹣winningchemistsaidin2001. WhenSacksreceivedtheLewisThomasPrizeforsciencewritingin2002thecitation荣誉状declareduSackspressesustofollowhimintounknownareasofhumanexperienceandforcesustorealizeoncetherethatwearefacingonlyourselves. 1ThefollowingstatementsarewrongEXCEPT. A.TheManWhoMistookHisWifeforaHatwasrankedamongthe25greatestsciencebooks B.AnthropologistonMarsledtoamovieinwhichSackswasactedbyRobinWilliams C.Sacksrecordedamanwhoregainedsightafteralifetimeblindness D.Awakeningsisoftencitedbyneuroscientiststoprovethemysteryofhumanbrain 2WhywasSackscalledoneofthegreatestwritersofscienceoverthepast50years? A.HewasborninLondonandmostfamousforhiswriting. B.Hewroteaseriesofbookstheinfluenceofwhichwasgreat. C.Hewasabrilliantneurologistandhadatrulybeautifulmind. D.HereceivedtheLewisThomasPrizeforsciencewritingin2002. 3Whichofthefollowingistrueaccordingtothepassage? A.OliverSackslosthiscolorvisioninacaraccident. B.OliverSackswontheNobelPrizein2002. C.Awakeningswasfilmedin1973inwhichRobinWilliamsactedasSacks. D.OliverSacksshowedrespectforhumanityinhisbooks. 4Thepassageismainlyabout. A.theawardsOliverSacks'won B.thelifeexperiencesofOliverSacks C.theinfluenceofOliverSacks'works D.thereasonswhyOliverSackssucceeded
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将函数fx=sin2x+φ0<φ<π的图象向右平移个单位长度后得到函数的图象则函数fx的一个单调减区间为
已知函数fx=|2x+m﹣1|+|2x﹣3|. 1当m=2时求不等式fx≤6的解集 2若fx≤|2x﹣6|的解集包含区求m的取值范围.
Ifyouwearglasseschancesareyouaresmarter.ResearchpublishedinthefamousBritishjournalNatureCommunicationshasfoundthatpeoplewhodisplayedhigherlevelsofintelligencewerealmost30percentmorelikelytowearglasses. Thescientistsstudiedthegenesofthousandsofpeoplebetweentheagesof16and102.Thestudyshowedintelligencecanbeconnectedtophysicalcharacteristics.Onecharacteristicwaseyesight.In3outof10peoplewhoweremoreintelligenttherewasahigherchancetheyneedglasses.Scientistsalsosaidbeingsmarterhasotherbenefits.Itisconnectedtobetterhealth. Itisimportanttoremembertheseareconnectionswhicharenotprovencauses.Scientistscallthiscorrelation.Justbecausesomethingisconnectedtosomethingelsedoesnotmeanoneofthosethingscausedtheother.Andit'sworthnotingthatwhatconstitutes构成intelligenceissubjectiveandcanbedifficultifnotimpossibletomeasure. Forgetgenesthough.Plentyofproofshowswearingglassesmakespeoplethinkyouaremoreintelligentevenifyoudonotneedglasses.Anumberofstudieshavefoundpeoplewhowearglassesareseenassmarterhard﹣workingandhonest.Manylawyersusethisideatohelpwintheircases.LawyerHarveySlovisexplainedthis.Glassessoftentheirappearancehesaid.Sometimestherehasbeenahugeamountofproofshowingthatpeoplehewasdefendingbrokethelaw.Hehadthemwearglassesandtheyweren'tfoundguilty. GlassesarealsousedtoshowsomeoneisintelligentinmoviesandonTVIdeasaboutpeoplewhowearglasseshavebeguntoshift.Peoplewhodonotneedglassessometimeswearthemforfashiononly.Theywanttolookworldlyorcool.Butnoteveryoneisimpressedbythisideathough.GQmagazinesaidpeoplewhowearglassesforfashionaretryingtoohardtolooksmartandhip时髦的.Howeverthathasn'tstoppedmanycelebrities名人fromhappilywearingglasseseveniftheydonotneedthem.JustenBieberisjustonehigh﹣profilefanoffashionglasses. 1Whatdoesthenewstudyshow? A.Peoplewearingglassesaresmarter. B.Peoplewearingglassesarehealthier. C.Wearingglassescanmakepeoplecleverer. D.WearingglassesisassociatedwithhigherIQ. 2WhatdoestheunderlinedwordcorrelationinParagraph3mean? A.Shift. B.Link. C.Proof. D.Consequence. 3Whydosomelawyersasktheirclientstowearglassesincourt? A.Becauseitcancreateamoralimage. B.Becauseitcanmisleadthewitnesses. C.Becauseitcanhighlightclients'qualities. D.Becauseitcanprovetheclients'innocence. 4Whatisthegeneralattitudetothosewhowearglassesforfashion? A.Positive. B.Negative. C.Mixed. D.Indifferent.
ForalongtimeIthoughtapresentandagiftwerenodifferent.Igrewupinahouseholdwherepresents1specialoccasionssaytherewerealwayspresentsforChristmasandourbirthdays. SowhenImarriedGarywhodidnotgivepresentsona2basisIhadtomakeanadjustment.Garydidnotwhollyavoidgift﹣givingthough.3noticinghowmanyhoursIspendonthe4hebroughthomeashoulderpad垫肩forthetelephonereceiver.Butmostlyhe5holidaysletaloneshopforearringsto6tomeshowinghisaffection. Itriedtochangehim7.IboughtbooksforhisbirthdaysandknittedhimhatsandsweatersforChristmas.8IbegantotellhimwhatIwantedgiving9instructionsbutgotnowhere. Lastyearwhenthesnowstorm10ourtownandhewasonbusinessIusedhispresent﹣roadscraper铲土机to11bothourdriveandourneighbor'sthinkinghow12earringswouldhavebeen.GaryhadwiselychosennotthethingI13butthethingthatheknewIwouldneed. I14begantounderstandthedifferencebetweenapresentandagift.Apresentisjustathing.Butagiftisbroaderandoftencannotbe15.Itisasmallactofkindnessthe16tobendtoanother'sneedsthesacrificeoftimeandeffort.17isagift.Anyexpressionofitfreelygivenisan18fromtheheartthatisimmeasurablybetterthanapresent. MyinsistenceonpresentsmusthaveseemedtoGaryalackof19.forthegiftshehadbeengivingallalongbutheneverstoppedgivingthem. GarywillbehomethisChristmasbutIdon't20apresent.Ialreadyhavethegreatestgift. 1A.marked B.involved C.expressed D.displayed 2A.daily B.rare C.temporary D.regular 3A.Therefore B.Once C.Then D.Besides 4A.gardening B.cooking C.telephone D.Internet 5A.missed B.hated C.abandoned D.ignored 6A.serve B.refer C.present D.relate 7A.bytradition B.byforce C.byexample D.bychance 8A.Yet B.Even C.Thus D.Still 9A.useful B.simple C.specific D.interesting 10A.struck B.disappeared C.melted D.passed 11A.clearup B.tearup C.buildup D.speedup 12A.priceless B.useless C.weightless D.colorless 13A.valued B.prepared C.preserved D.desired 14A.eventually B.definitely C.simply D.totally 15A.obtained B.discovered C.measured D.observed 16A.happiness B.willingness C.wisdom D.freedom 17A.Love B.Passion C.Insistence D.Motivation 18A.sharing B.offering C.following D.experiencing 19A.desire B.concern C.preparation D.appreciation 20A.purchase B.order C.expect D.evaluate
过双曲线的右焦点F作垂直于x轴的直线交双曲线于AB两点若△OABO为坐标原点为等腰直角三角形则该双曲线的离心率为
曲线y=x+1ex在点01处的切线方程为.
TopMusicFestivals Festivalseasonisjustkickingoffandthereisalottolookforwardtointheupcomingmonths. FireflyMusicFestival Manypeoplehaven'tthoughtofgoingtoDelawareforasummervacationbutmid﹣Juneisagreattimetoplanthistripifyoulovemusic.Headlinersforthisyear'sshowareTheWeekendMuseTwenty﹣OnePilotsChancetheRapperandBobDylan. Date:June15﹣182017 Location:DoverDelawareUSA MusicType:Rock Price:$79﹣$2499 RoskildeFestival ThisDenmarkmusicfestivalhasbeenalocaltraditionsince1971.Therewillbeninestagesforthisyear'seventstohostgroupsliketheFooFightersBlink182andTheLumineers.What'sinterestingaboutthisfestivalisthatinadditiontothebigheadlinersyoucanalsogettoknowup﹣and﹣comingregionalartistsfromDenmarkSwedenandNorway. Date:June24﹣July12017 Location:RoskildeDenmark MusicType:Rockemergingregionalartists Price:DKK995﹣DKK1995around$144﹣$289 SecretSolstice WithlongdarkandcoldwintersnobodycelebratessummerquitelikeIcelanders.ToseeforyourselfplanatriptoIcelandthisJunetocheckouttheSecretSolsticefestival.NotonlywillyouenjoyseeingbandslikeRadioheadandAfrikaBambaataabutyoucanalsoexperiencetheother﹣worldlylandscapesandgeothermal地热的springsnearbyaswell. Date:June15﹣182017 Location:ReykjavikIceland MusicType:EclecticIndie Price:€149﹣€1599around$160﹣$1725 MontrealJazzFestival AlljazzloversoweittothemselvestocheckouttheMontrealJazzFestivalatleastonceinalifetime.ThiseventbringstogethersomeofthebestnamesinjazzmusicaswellasdiverseR&Bfunk骤停打击乐andsoulartists. Date:June28﹣July82017 Location:MontrealQuebecCanada MusicType:JazzR&BSoulFunk Price:$27.25﹣$210.25 1Whatiscommontothemusicfestivalsmentionedinthetext? A.TheyareheldinEurope. B.Theirmusictypesarerockandhip﹣hop. C.Theyaregivenintheopenair. D.Theytakeplaceinsummer. 2WhatcanweinferaboutDelawarefromthetext? A.Itisthecityofmusic. B.Itisnotasummerdestination. C.ItisthehomeofBobDylan. D.Itisacityofhighexpense. 3WhatisthepurposeofIcelanderstoholdtheSecretSolsticefestival? A.Towelcomesummer. B.Tomemorizethepastwinter. C.Tocelebratethecomingofspring. D.Toadvisethelocalbeautifullandscapes.
WhenMr.WangaChinesecalligraphy书法masterandpainterinvitedmetohisstudioIgotextremely1delight.Whatatreat! Hisapartmentdoublesashisstudio2hecreatescalligraphyworksandpaintingsaswell.Thelivingroomhasalongdeskwithacollectionof3brushofvaryingsizestwobiginkpotsandapairofpaperweights. Mr.Wangshowedhislatestworkascroll卷轴oftheGreatWallatBadaling4winditswayalongthesteephillswhich5recognizeasaWorldHeritageSitebytheUnitedNationsin1987.Thebeautyoftheseven﹣meter﹣longscrollpaintingwasbeyond6describe. Hetoldmesomeonehadofferedalargeamountofmoneyforthepaintingbutherefused7partwithitashewantedtodonatetotheNationalMuseum. AfterthatMr.WanginvitedmetopracticecalligraphyanditwasthefirsttimethatIhad8trueexperiencedthebeautyoftheline.Itwasthen9InoticedMr.Wangappearedtohaveahealthybody.Iwonderedifpracticingcalligraphykepthimsofit.Whetherthatistrueonethingiscertain;asMr.Wangput10Onlydoonethinganddoitwell﹣﹣﹣that'sthesecrettosuccess
Earlierthismonthastudyshowedthatbeescanteachthemselvestoplayfootball.Theycanlearnbywatchingandratherthancopywhattheyhaveseenchangeittomakeitbetter.Beesalsohaveaclevertrickforhelpingtheirfriendsfindlunch.Newresearchshowsthatbeesleavesmellylittlefootprintsonflowersthathelpthemknowwhatflowerstheyandtheirfamilymembershaverecentlyvisited. ThediscoverywasmadebyscientistsfromUniversityofBristolwhoreportthesesmellyfootprintshelpbeesdistinguishbetweentheirownscent气味thescentofarelativeandthescentofastranger.Andbyusingthisabilitybeescanimprovetheirsuccessatfindinggoodsourcesofafoodandavoidflowersthathavealreadybeenvisitedandminedofnutrients. TheBristolteamperformedthreeseparateexperimentswithbumblebees大黄蜂inwhichtheywererepeatedlyexposedtorewardingandunrewardingflowersatthesametimethathadfootprintsfromdifferentbeesattachedtothem.Eachflowertypeeithercarriedscent﹣marksfrombumblebeesofdifferingrelatednessorwereunmarked.Themarkswereeitherthebee'sownmarkssistersfromtheirnestorstrangersfromanothernest. Thestudyshowsthatnotonlycanbumblebeestellthemarksoftheirownnestmatesfromstrangersbuttheycanalsodiscriminatebetweenthesmelloftheirownfootprintsandthoseoftheirnestmatesisterswhichcouldhelpthemtorememberwhichflowerstheyhavevisitedrecently.Butitdoesn'texplainhowtheyusethatinthewild.Theymaydetectthefootprintsoftheirfriendsandkeepmovingonsincethatflowermaybetappedout.Ortheymaysmellabitoffamiliarfootsmellanddiveinseeingitasamarkerthatnectar花蜜ispresent. 1WhatcanweinferaboutbeesinParagraph1? A.Theyaresmartlearners. B.Theyhavestrongfamilyties. C.Theyenjoysmellyfootprints. D.Theylikeplayingtricksonothers. 2WhatdoesthisabilityinParagraph2referto? A.Findinggoodsourcesoffood. B.Followingotherbees'footprints. C.Tellingthesmellsoffootprintsapart. D.Recognizingdifferenttypesofflowers. 3Whatcanwelearnfromthefindingsoftheexperiments? A.It'seasierforBumblebeestorecognizetheirfriends. B.It'sunclearhowbumblebeesusetheirabilityinthewild. C.Bumblebees'memorycanbesignificantlyimproved. D.Bumblebees'footprintscangivethemasenseofidentity. 4Whatisthemainideaofthetext? A.Differentflowersattractdifferentbees. B.Beeshaveanewtrickofsurvivinginthewild. C.Bumblebeesmaysmellfootprintstokeeptrackoffood. D.Bumblebeescangiveoffuniquescentstoattractothers.
FourTipsforHighSchoolGraduates Overthree﹣millionhighschoolstudentsaregraduatingthisspringintheUnitedStates.Manyofthemwillheadtouniversityinthefall.Thetransition过渡fromhighschooltocollegeisamajoroneandsuccessfuladjustmenttocollegehaslifelonginfluences. Maybeyouareabouttomakethistransitionyourselforhavechildrenwhoareabouttoleavethenest.1Ifyouknowsomeonewhoismakingthistransitionorknowparentsguidingtheirsoon﹣to﹣beadultkidsthroughthistimepleasetakeamomenttosharethiscollectionofresearch﹣basedtipswiththem. Beopentomakingnewfriendsassoonasyousetfootoncampus.Evenduringorientation迎新会!2Yoursuccessincollegedependsinpartonsurroundingyourselfwithotherswhocansupportyouandhelpyouhavefun. 3Successfuladjustmentisaboutreachingoutforhelpwhenyouneedit.Thismeanstryingtofindtheanswersonyourownfirstbutthencontactingthosewhocanhelpyouwhenyoucan't.Thatiswhattheyaretherefor! Leanonyourfamily.Familysupportcangiveyoucomfortwhenclassesgethardoryouarestressedaboutfinals.4Strongsupportfromfamilyislinkedtolowerlonelinessanddepressionduringthefirstyearofcollegeandhigheracademicadjustmentincludingmotivationandconcentration. Beconfident.Feelinganxietyaboutcommunicatingwithfellowsprofessorsandspeakingupinclassisassociatedwithloweradaptationduringthetransitiontocollege.Oneofthebestwaystoincreaseyourcommunicationconfidenceistopractice!5 A.Thislistisforyou. B.Themoreyouspeakupinclasstheeasieritbecomes. C.Don'tbeafraidtotalktoyourprofessorsorteachingassistants. D.Joiningclubsisalsolinkedtofeelingsofbelongingatcollege. E.Yourprofessorsandteachingassistantswanttoseeyousucceedintheirclasses. F.Almosteveryoneisinthesameboatasyouarehopingtomakefriendsquickly. G.Familymemberscangiveyouadviceandhelpyousolveproblemsifyouneedhelp.
TheCreatorofMiddleEarth JohnRonaldReuelTolkienbetterknownasJ.R.R.Tolkienwasbornin1892inSouthAfrica.Hisparentshadmovedtherelookingfor1betterjobforhisfather.Threeyears2latehismothertookhimonatriptoEnglandtovisitfamily. Whiletheywereawaytheyreceivedterriblenewsthathisfatherhaddied. 3growupwithoutafathermusthavebeendifficultforTolkien.Worsestillwhenhewasonlytwelveyearsoldhismotheralsopassedaway.Asachildhehadagreatpassionforlanguageandin1908hewenttoOxfordUniversity4studylanguagesandliterature.In1915hejoinedthearmyandfoughtinthebattleagainsttheGermans.Butsoonhebecametooilltofightandreturned5Englandthefollowingyear.Hedidn'thavea6satisfychildhoodhimselfsoaroundin1933storyofahobbit霍比特人hespentmuchtimetellinghischildrenfantasy7calledBilbo.Hefirstputitinwritingin19368turnedouttobeasurprisinghit. Thepublisheraskedhimtowriteanother.Hedidsoandin1948publishedTheLordoftheRingswhich9publishinthreevolumesbetween1954and1955. Tolkien10ageeighty﹣onediedin1973.
已知函数fx=ex1﹣ax﹣x2. 1求fx的单调区间 2若x≥0fx≤1求实数a的取值范围.
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