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已知等比数列{an}满足a1=4,a1a2a3=a4a5>0,则公比q=( )
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高三下学期数学《》真题及答案
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1已知两个等比数列{an}{bn}满足a1=aa>0b1-a1=1b2-a2=2b3-a3=3若数列
在数列{an}中已知a1=2an+1=4an-3n+1n∈N*.1设bn=an-n求证:数列{bn}
在等比数列{an}中an>0且a1·a2a7·a8=16则a4+a5的最小值为.
已知数列{an}满足:a1=1a2=22an=an-1+an+1n≥2n∈N*数列{bn}满足b1=
在等差数列{an}中已知a1=3a4=121求数列{an}的通项公式2数列{bn}为等比数列且b1=
已知等比数列{an}中a1+a2=9a1a2a3=27则{an}的前n项和Sn=__________
已知等比数列{an}满足a1=3且4a12a2a3成等差数列则a3+a4+a5=
33
84
72
189
若等比数列{an}满足a2a4=则a1a5=.
已知-1a1a28成等差数列-1b1b2b3-4成等比数列那么的值为
-5
5或-5
-
已知等差数列{an}满足a1=2且a1a2a5成等比数列.求数列{an}的通项公式.
已知公差不为0的等差数列{an}的前n项和为SnS3=a4+6且a1a4a13成等比数列.Ⅰ求数列{
已知等比数列{an}为递增数列若a1>0且2an+an+2=5an+1则数列{an}的公比q=___
已知等比数列{an}为递增数列.若a1>0且2an+an+2=5an+1则数列{an}的公比q=.
已知各项均为正数的等比数列{an}中a1a2a3=5a7a8a9=10则a4a5a6等于
5
7
6
4
已知{an}是等比数列a1=2a4=54{bn}是等差数列b1=2b1+b2+b3+b4=a1+a
已知等比数列{an}的前n项和为Sn若S2n=4a1+a3+a5++a2n-1a1a2a3=27则a
27
81
243
729
在公差为d的等差数列{an}中已知a1=10且a12a2+25a3成等比数列.1求dan;2若d
等比数列{an}的前n项和为Sn已知S3=a2+10a1a5=9则a1=.
已知等比数列{an}满足a1=a3a5=4a4﹣1则a2=___________
若数列{an}中an≠0n≥1a1=前n项和Sn满足an=n≥2则是
首项为2、公比为
的等比数列
首项为2、公比为2的等比数列
既非等差数列也非等比数列
首项为2、公差为
的等差数列
首项为2、公差为2的等差数列
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一只铭牌上标有“6V0.6A”的灯泡接入电路中工作时其两端电压与电流之间的关系的图象如图所示根据图象可以计算出当该灯泡两端电压为4.0V时其电阻大小为8Ω当该小灯泡两端的电压为2V时其消耗的电功率为0.6W.
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Robotsarenowbeingemployednotjustfordangeroustaskssuchasdiscoveringminesorrescuingpeopleindisasters.Theyarealsofindingapplicationashouseholdhelpsandasnursingassistants.Asincreasingnumbersofmachinesequippedwiththelatestartificialintelligencetakeonagrowingvarietyofspecializedandeverydaytasksthequestionofhowpeopleseethemandbehavetowardsthembecomesevermoreurgent. AteamledbySariNijssenofRadboudUniversityandMarkusPaulusProfessorofDevelopmentalPsychologyatLudwig﹣Maximilians﹣UniversitaetLMUhavecarriedoutastudytodeterminethedegreetowhichpeopleshowconcernforrobotsandbehavetowardsthembasedonmoralprinciples. AccordingtoSariNijssenthestudysetouttoanswerthefollowingquestionUnderwhatcircumstanceswouldadultsbewillingtosacrificerobotstosavehumanlives?Theparticipantswerefacedwithahypothetical假设的moraldilemmaWouldtheybepreparedtoputasinglepersonatriskinordertosaveagroupofinjuredpersons?Inthesituationspresentedtheintendedvictimwaseitherahumanahumanoidrobotthathadbeenhumanized人性化的tovariousdegreesorarobotthatwasclearlyrecognizableasamachine. Thestudysuggestedthatthemoretherobotwashumanizedthelesslikelyparticipantsweretosacrificeit.Situationsthatincludedvividstoriesinwhichtherobotwasdescribedasamercifulbeingorasacreaturewithitsownunderstandingsexperiencesandthou^itsweremorelikelytostopthestudyparticipantsfromsacrificingitintheinterestsofanonymous无名的humans. ThisresultindicatesthatourstudygroupattachedacertainmoralstatustotherobotsaysPau﹣lus.Onepossiblesuggestionofthisfindingisthatattemptstohumanizerobotsshouldnotgotoofar.Sucheffortscouldcomeintoconflictwiththeirintendedfunction﹣tobeofhelptous. 1Whathasbecomeaconcernaboutrobots? A.Howtohumanizethem. B.Howtotreattheminlife. C.Howtousethemeffectively. D.Howtofindmoreapplications. 2Inthestudytheparticipantsprobablyhavetodecide. A.whentosacrificearobot B.wheretoexperiencerisks C.whichrobottoworkwith D.whatrobotsshouldbelike 3WhatcanbeinferredfromPaulus'words? A.Humanizedrobotsofferlesshelptopeople. B.Humanizingrobotstoomuchmaybeimproper. C.Certainmoralstatusshouldbeattachedtorobots. D.Conflictsoftenhappenbetweenhumansandrobots. 4Whichofthefollowingwouldbethebesttitleforthetext? A.RobotsAMustforFuture B.HumanizedRobotsANewTrend C.RobotSavedPeopleTaketheHit D.HumanizedRobotsReplaceHuman
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Aroundtheworldmalnutrition营养不良hasbecomeaproblemthatcosts﹩3.5trillionperyearaccordingtothelatestGlobalNutritionReport1givesananalysisoffoodandnutritionissueseachyear. Althoughmostcountrieshavefallenshortintheirefforts2dealwithpoornutritionandfoodinsecuritytheUSappearstobebadlyofftrackthereportfound.Theworld's3largeeconomycontinuestosufferfromhighratesofobesitydiabetesandanemia贫血accordingtothedataandhasmorethanamillionoverweightchildren. Malnutritionisresponsibleformoreill﹣health4anyothercause.5healthconsequencesofoverweightandobesitycontributetofourmilliondeaths6globe.CorinnaHawkesdirectoroftheCenterforFoodPolicy7writeinthereport. Accordingtothestudymostcountrieshaveatleasttwoissuesrelatedtomalnutrition.Themostseriousissuesarechildrenwhoareeitheroverweightanemic8sufferfromundevelopedgrowth.Overallmalnutritioncontributestoabouthalfofallchildhooddeathstheresearchshowed.Andthose9affectmaynotbeabletogetasgoodajobastheycouldhaveiftheyhadbeenfedwell.Italsopreventsthem10beabletocontributetosocietyandtheeconomyaswellastheywouldhaveinahealthierenvironment.
假设你是李华你的英国笔友Tony即将完成学业上周他来信就是否到中国工作询问你的意见.请根据以下提示回一封电子邮件内容包括 1建议他来中国就业; 2阐述你的理由就业机会多专业受欢迎不同的文化体验等; 3承诺可以提供帮助. 注意1词数100左右开头和结尾已给出不计入总词数; 2可适当增加细节以使行文连贯. DearTony Yours LiHua
小郑同学利用手边的器材天平和砝码空玻璃瓶足够的水某种液体顺利的完成了测量“某种液体密度”的实验.下面给出的是小郑完成实验时的第一个步骤请你将实验步骤补充完整.已知水的密度为ρ水待测液体足够多 1用调节好的天平和砝码测出空玻璃瓶的质量m0并记录在表格中 2用调节好的托盘天平测量并记录在表格中 3用调节好的托盘天平测量并记录在表格中 液体密度的计算公式ρ液=.
在水平桌面上探究平面镜成像特点的实验装置与实验情景如图所示请完成下列问题 1如图甲所示在实验过程中要用透明的平板玻璃代替平面镜.如果现有5mm厚和2mm厚的两块玻璃板应选择2mm厚的玻璃板做实验其目的是减小玻璃板厚度导致的两个像而产生的重影现象对实验结果的影响. 2如图乙所示如果玻璃板没有与水平桌面竖直放置则在实验操作过程中会出现的情况是桌面上玻璃板后蜡烛无法和玻璃板前蜡烛的像重合 3如图丙所示经过三次实验在正确的实验操作过程中要分别标记像A′B′C′与物ABC相应的位置为了得到更多的实验结论接下来应该进行的实验操作是将像和物位置的对应点相连接其目的是为了判断像物连线与镜面是否垂直以及像和物到平面镜的距离相等.
如图是标准大气压下质量为1g的某液体的体积﹣﹣温度图以下说法正确的是
我们可以用图示的电路图测量未知电阻RX的阻值.调节电路当电压表示数U为3.0V时电流表的示数为0.3A.如果考虑到电流表的电阻值RA为0.5Ω待测电阻RX′的阻值应为Ω.
由金属杆组成如图所示的导轨其中水平面上两平行导轨足够长且全部置于竖直向上的磁场中与倾斜放置的导轨ABCD平滑且固定连接.将一金属棒ab从倾斜导轨上一定高度由静止释放运动过程中始终与导轨垂直接触且不受摩擦因为从能量转化的角度简述理由所以ab棒在水平导轨上的运动情况是选填加速减速或匀速.
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