首页
试卷库
试题库
当前位置：
X题卡
>
所有题目
>
题目详情
已知xy＞0，则的最小值为 ．
查看本题答案
包含此试题的试卷
高一下学期数学《》真题及答案
点击查看
你可能感兴趣的试题
已知x＞0y＞0x+2y+2xy＝8则x+2y的最小值为．
已知xy＞0则的最小值为．
已知x>0y>02x+8y-xy=0那么x+y的最小值为.
已知正数xy满足x＋2y－xy＝0那么x＋2y的最小值为
8
4
2
0
已知正实数xy满足xy+2x+3y=42则xy+5x+4y的最小值为.
已知x＞0y＞0且2x+8y﹣xy=0求 1xy的最小值 2x+y的最小值．
已知x＞0y＞0且x+2y﹣xy=0则x+2y的最小值为．
已知x＞0y＞0且2x+8y﹣xy=0则x+y的最小值为．
已知x＞0y＞0x＋2y＋2xy＝8则x＋2y的最小值是多少
已知则fx有
最大值为0
最小值为0
最大值为－4
最小值为－4
已知两点
(3,0)，
(0,4)，动点P.(x，y)在线段AB上运动，则xy( ) A.无最小值且无最大值 B.无最小值但有最大值
有最小值但无最大值
有最小值且有最大值
已知xy都是正实数且x＋y－3xy＋5＝0.1求xy的最小值2求x＋y的最小值.
已知正数xy满足x+2y﹣xy=0则x+2y的最小值为
8
4
2
0
已知正数xy满足x2+2xy﹣3=0则2x+y的最小值是.
若正数xy满足x+4y﹣xy=0则x+2y的最小值为
已知xy＞0则的最小值为．
已知正数xy满足则xy满足
最小值12
最大值12
最小值144
最大值144
已知fx＝x＋－2x
最大值为0
最小值为0
最大值为－4
最小值为－4
已知.1求xy的最小值2求x+y的最小值.
已知x>0y>0x+3y+xy=9则x+3y的最小值为.
热门试题
更多
用双缝干涉测光的波长．实验装置如图a所示已知单缝与双缝的距离L1＝60mm双缝与屏的距离L2＝700mm单缝宽d1＝0.10mm双缝间距d2＝0.25mm．用测量头来测量光屏上干涉亮条纹中心的距离．测量头由分划板目镜手轮等构成转动手轮使分划板左右移动让分划板的中心刻度对准屏上亮纹的中心如图b所示记下此时手轮的读数转动测量头使分划板中心刻线对准另一条亮纹的中心记下此时手轮上的刻度． ①分划板的中心刻线分别对准第1条和第4条亮纹的中心时手轮上的读数如图c所示则对准第1条时读数x1＝mm对准第4条时读数x2＝mm相邻两条亮纹间的距离△x＝mm． ②计算波长的公式λ＝用题设的字母表示求得的波长值是nm保留三位有效数字．
放在水平地面上的一物块受到方向不变的水平推力F的作用F的大小与时间t的关系和物块速度v与时间t的关系如图所示．取重力加速度g＝10m/s2．由此两图线可以求得物块的质量m和物块与地面之间的动摩擦因数μ分别为
一定质量的理想气体分子力不计体积由V膨胀到V′．如果通过强不变的过程实现对外做功大小为W1传递热量的值为Q1内能变化为△U1如果通过温度不变的过程来实现对外做功大小为W2传递热量的值为Q2内能变化为△U2则
一定质量的气体在等温变化过程中可视作理想气体下列物理量中将发生变化的是
为了解某中学学生课余生活情况对喜爱看课外书体育活动看电视社会实践四个方面的人数进行调查统计．现从该校随机抽取n名学生作为样本采用问卷调查的方法收集数据参与问卷调查的每名学生只能选择其中一项．并根据调查得到的数据绘制成了如图所示的两幅不完整的统计图．由图中提供的信息解答下列问题 1求n的值 2若该校学生共有1200人试估计该校喜爱看电视的学生人数 3若调查到喜爱体育活动的4名学生中有3名男生和1名女生现从这4名学生中任意抽取2名学生求恰好抽到2名男生的概率．
100mL水与100mL酒精混合后体积小于200mL这时因为
15分Juliealwaysthoughtofherselfasaneasy﹣goingandtolerantperson61putupwithpeople'sdifferences.Shehardlyeverbecameupsetaboutanythingand62believethatifyoutreatedpeoplewelltheywouldcooperatewithyou.ThatisuntilAlexandHarrymovedinnextdoor.Atfirstwhentheirmusicwokeheratnightshewasjustabit63annoy.ShesaidtoherselfTake64easy.Imakealotofnoisesometimes.Iwillgoroundandcomplaininasniceawayaspossible.WhensheknockedatAlexandHarry'sdoorshesaid.65honestspeakingyourloudmusichasbotheredme.Doyouthinkyoucouldturnitdownabit?Theyjustsmilednot66feelashamedatallandthenAlexsaidYoucanthinkwhateveryoulikeasfaraswe're67concern.ThentheyshutthedoorinJulie'sface.InthefollowingweekthenoisecontinuedandJuliefeltangrybutwas68determinenottolosehertemper.NexttimeshecalledonnextdoorshegaveHarryandAlexapresent.It'sjustacakeImade69you.Pleaseacceptmysincere70apologizeforlasttime!Andthatdaythenoisestopped. Whatarelief!thoughtJulie.Nowthere'ssomepeaceandquietnessandIcanreadmyfavoritebook.
如图所示汽缸内封闭一定质量的某种理想气体活塞通过滑轮和一重物连接并保持平衡已知活塞距缸口h＝50cm活塞面积S＝10cm2封闭气体的体积为V1＝1500cm3温度0℃大气压强p0＝1.0×105Pa物体重G＝50N活塞重力及一切摩擦不计．缓慢升高环境温度封闭气体吸收了Q＝60J的热量使活塞刚好升到缸口．求 ①汽缸内气体对外界做多少功 ②气体内能的变化
在物理学发展过程中许多科学家做出了杰出贡献．下列说法正确的是
下列哪些情况下的物体可以看成质点
在“利用打点计时器测定匀加速直线运动加速度”的实验中打点计时器接在50Hz的低压交变电源上．某同学在打出的纸带上每5点取一个计数点共取了ABCDEF六个计数点每相邻两个计数点间的四个点未画出．从每一个计数点处将纸带剪开分成五段分别为abcde段将这五段纸带由短到长紧靠但不重叠地粘在xOy坐标系中如图2所示由此可以得到一条表示v﹣t关系的图线从而求出加速度的大小． 1①请你在xOy坐标系中用最简洁的方法作出能表示v﹣t关系的图线作在答卷纸上②并指出哪个轴相当于v轴答 2从第一个计数点开始计时为求出0.15s时刻的瞬时速度需要测出哪一段纸带的长度答 3若测得a段纸带的长度为2.0cme段纸带的长度为10.0cm则可求出加速度的大小为m/s2．
某交流电电源电压的瞬时值表达式为u＝6sinl00πtV则下列说法中正确的是
如图为“研究电磁感应现象”的实验装置． 1将图中所缺的导线补画完整． 2如果在闭合电键时发现灵敏电流计的指针向右偏了一下那么合上电键后可能出现的情况有 a．将A线圈迅速插入B线圈时灵敏电流计指针将向偏转一下． b．A线圈插入B线圈后将滑动变阻器触头迅速向左拉时灵敏电流计指针将向偏转一下．
6分Publicserviceadvertisingisdesignedtoinformthepubliconissuesthatarefrequentlyconsideredtobeinthegeneralbestinterestsofthecommunityatlarge.Typicallyitreflectsapoliticalviewpointphilosophicaltheoryreligiousconceptorhumanitariannotion观念.ItisalsocommonlyreferredtoasapublicserviceannouncementPSAoracommunityserviceannouncementCSA.Theadsareusuallybroadcastonradioortelevisionbuymayalsoappearinnewspapersormagazines.Theyarecommoninindustrializedcountiesthroughouttheworld. PSAsarecommonlyaimedatchangingpublicattitudesbyraisingconsciousnessaboutparticularissues.HealthconservationandsafetythemesarepopularinmanyPSAs.Thepublicserviceadvertisingcampaignsareoftensponsoredbytradeassociationscivicorganizationsnon﹣profitinstitutionsorreligiousgroups. Mostpublicserviceadvertisinginvolvesjointeffortsoftheprivateandpublicsectors.Non﹣profitgroupsandgovernmentagenciescommonlyteamupwithprivatemassmediapromotionandadvertisingfirmstoproducespotsforradiotelevisionandprintmedia.Mostcommonlythenon﹣profitagencycreatesthemessageandanadvertisingfirmdevelopsthecampaignpolishesittomeetindustrystandardsandplansitsdistributionallfreeofcharge.Televisionandradiostationsusuallybroadcasttheseadsatnochargeandmagazinesandnewspaperscustomarilypublishthemforfreeaswell. InrecentyearsithasbecomecommonplaceforU.S.televisionstationstofeaturepublicserviceadvertisingspotsimmediatelyfollowingabroadcastthathasfocusedonanissueconsideredsensitiveandofconcerntomanymembersofthegeneralpublic.ThesePSAbroadcastsgenerallyofferaddresseswebsitesandtoll﹣freetelephonenumbersforinformationsources.Someofthetopicsfocuse4doninthePSAshaveincludedchildabuseAIDSandcivilrights. 29.What'sthemainpurposeofPSAs? A.Tosellmoreproductsthroughsomespecialways. B.Tochangeconsumer'sattitudesthroughmedia. C.Toimprovepeople'sawarenessaboutspecialissues. D.Tomakemorefamousstarsknowntothepublic. 30.HowdoestheauthorlikePSAs? A.HethinksitgoodtomakePSAs. B.HeisagainsttheideaofPSAs. C.HeiscuriousabouttheideaofPSAs. D.HethinksPSAsarecompletelytomakemoney. 31.Whatcanwelearnfromthepassage? A.MostofthePSAsaremadebythegovernment. B.PSAswillmakebigprofitsfortradeassociations. C.PSAsoffervarioustopicsinmanydifferentareas. D.PSAsaremainlybroadcastontelevisioncurrently.
如图示是一电源变压器一次绕组匝数为550匝接电源220V它有两个二次绕组一个电压为36V负载功率为36W另一个电压为12V负载功率为24W不计空载电流求 1两个绕组的匝数 2一次绕组的电流．
如图足够长的斜面倾角θ＝37°．一个物体以v0＝12m/s的初速度从斜面A点处沿斜面向上运动．物体与斜面间的动摩擦因数为μ＝0.25．已知重力加速度g＝10m/s2sin37°＝0.6cos37°＝0.8．求 1物体沿斜面上滑时的加速度大小a1 2物体沿斜面上滑的最大距离x 3物体沿斜面到达最高点后返回下滑时的加速度大小a2 4物体从A点出发到再次回到A点运动的总时间t．
关于电磁波和相对论下列说法正确的是
如图⊙O是△ABC的外接圆AB为直径∠BAC的平分线交⊙O于点D过点D作DE⊥AC分别交ACAB的延长线于点EF． 1求证EF是⊙O的切线 2若AC＝4CE＝2求的长度．结果保留π
如图所示的电路中R1是定值电阻R2是光敏电阻．已知光敏电阻的阻值随着光照强度的增加而减小电源的内阻不能忽略．闭合开关S当光敏电阻上的光照强度增大时下列说法中不正确的是
关于多普勒效应下列说法正确的是
先化简再求值1﹣÷其中a＝sin30°．
某物体运动的速度图象如图根据图象可知
如图所示置于水平地面的透热气缸中活塞封闭着一定质量的空气活塞与缸壁无摩擦且不漏气当大气压强保持不变而环境温度逐渐升高的过程中以下说法正确的是
下列说法正确的是
如图反比例函数y＝k≠0的图象与正比例函数y＝2x的图象相交于A1aB两点点C在第四象限CA∥y轴∠ABC＝90°． 1求k的值及点B的坐标 2求tanC的值．
8分FSCMASQUERADECOSTUME&PERFORMANCECOMPETITION2017 Aspecialcostumecontest比赛justforkids!ThiscontestwillbeRunwaystyle.Contestantscanwearcostumesboughtinstoresormadeathome.Hereareinformationrulesandregulationsthatyoushouldknow. TimeSeptember20th2017 Entryfeefree Awardswillbegivenforthefollowingcategories ●Bestinshow ●BestIndividualunder5yearsold ●BestIndividual5﹣9yearsold ●BestIndividual10﹣13yearsold ●BestGroup Competitionrules 1.Oneentryperperson. 2.Thecompetitionislimitedto50entrieswithnoexceptions. 3.Thereisaperformancetimelimitof90secondsforindividualsand3minutesforgroups. 4.Thiscontestisonlyopentochildrenaged13yearsoryounger.Parentsmaywalkthestagewiththeirchildren. 5.Allcostumesmustcomefromanestablishedcartooncomicbookvideogamenovelormovie. 6.Allcontestantsmustfillouttheentryformfirst. 7.Noharmfulorpotentiallyharmfulmaterialswillbeallowed. Whocanenter? Allattendeeswhohaveaneventbadge徽章forFloridaSuperconcanenterthiscontest.Participantscanenterasindividualsoringroups. 1Registeronline.Thisisthemostpreferredmethod.Youwillreceiveanemailconfirmation.TheonlineentrywillbecutoffonJuly202017atmidnight. 2Registerattheconvention大会.ParticipantswillbeabletosignupforthecontestattheCOSPLAYBOOTHTBAlocatedintheMainExhibitionHall.Filloutandreturntheentryformtotheregistrationtable.Youwillbegivenacontestantnumberandfurtherinformation.Everyonemustbesignedinandallthefarmsmustbehandedinby400p.m.onJuly212017. RollCall Alltheentrantsmustshowup30minutespriortothecompetitionforrollcallatBoothTBA.Ifyouhaveanyquestionspleasee﹣mailusatinfo@superconventions.com. 21.Whatkindofcostumesshouldcontestantswear? A.Anystyleofcostumesboughtinstores. B.Anystyleofcostumesmadeathome. C.Costumesdeliveredbythecompetitionorganization. D.Costumesdesignedfromaspecialthemeasregulated. 22.Whichcompetitionrulemustcontestantsfollow? A.Onecanattendnolessthanoneprogram. B.One'sperformanceislimitedto3minutes. C.Onemustfilltheformbeforeattendingit. D.Onecanchooseanymaterialheorshelikes. 23.Ifyouwanttoattendthecompetitionyoumust. A.haveaneventbadge B.beaccompaniedbyyourparents C.paythefeeasregulated D.beover13yearsold 24.Thecontestantsregisteringonlineshould. A.showup30minutesbeforethecompetitionfortheroll﹣call B.registertheinformationbySeptember20th2017 C.handintheformby400p.m.onJuly212017 D.fillintheformafterreceivingtheemailconfirmation.
如图所示一直立的汽缸用一质量为m的活塞封闭一定质量的理想气体活塞横截面积为S气体最初的体积为V0最初的压强为汽缸内壁光滑且缸壁导热性能良好．开始活塞被固定在A处打开固定螺栓K活塞下落经过足够长时间后活塞停在B处设周围环境温度保持不变已知大气压强为P0重力加速度为g若一定质量理想气体的内能仅由温度决定．求 ①活塞停在B点时缸内封闭气体的体积V ②整个过程中通过缸壁传递的热量Q．
某同学在做“用单摆测重力加速度”实验中先测得摆线长为l摆球直径为d然后用秒表记录了单摆振动50次所用的时间为t．他测得的g值偏小可能的原因是
10分HowtoTurnYourDreamsintoAReality Doyouhavedreamsvisionsorplansaboutthingsyou'dlovetohaveoraccomplish?Ofcourseyoudo!Wealldo.Unfortunatelydreamingistheeasypart36Thegoodnewsisthatthereareproventechniquesthatcangetyoufromwhereyouaretowhereyouwanttobe.Followthisprocesstobringyourdreamstofruition Turnyourdreamintoagoal. Whenyouhaveagoalyouhaveatruetarget.Foragreaterchanceofsuccessyourplanshouldhaveadeadlineanditmustbemeasurable.37Giveyourselfthegiftofsettingadeadlineandthingswillstarttohappen.Makeyourgoalasdesirableaspossiblewithoutbeingunrealistic.Ifyoufeelthatyourgoalisunreasonableit'smuchmoredifficulttoencourageyourselftoactuallypursueit. Prioritize优先化yourgoaldaily. 38Yougiveinstructionstoyourbrainthousandsoftimesaday.LetyourmindknowthatyourgoalissomethingmoreimportantthanIfeellikeeatingahamsandwichorIneedtostopatthegrocerystoreonthewayhome. 39 Achievingdifficultgoalscanrarelybeaccomplished.aloneyou'relikelytoneedsomehelpandguidance.Lookatthelistyoumadeandseewhatyoualreadyhaveinyourlifethatcouldhelpyouonyourpath. Trackyourprogress. Measureyourprogresseachday.Useoldfashionedpaperandpencilorgrabthelatestsmartphoneapp.40Youcanonlyadjustyourapproachifyouknowhowyou'redoing.Considermakingachartifthat'sapplicabletoyourgoal. A.Classifyyouravailableresources. B.Makealistofnegativeassociations. C.Readandwriteyourgoaleachday. D.Turningthosedreamsintoarealityisthechallenge. E.Trackingrscritical关键的tomakingcontinuedprogress. F.Itissaidthatdreamsaregoalswithoutadeadline. G.Somakealistofallthenegativestuffthatslipintoyourmind.
一列简谐横波沿x轴正向传播t＝0时刻的波形如图所示质点振动周期T＝0.2s．求 1波的振幅A波长λ波速v 2画出平衡位置在x＝1.5m处质点以该时刻为计时起点的振动图象．至少画一个周期并在图中标上周期半周期和振幅的数值
热门题库
更多
教案备课库
高一上学期数学
高一上学期化学
教案备课库
教案备课库
教案备课库
高一上学期物理
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
湘公网安备 43130202000226号