填空题级数的收敛半径R=________．

填空题

填空题设，其中f可导，且f"(0)≠0，则=________．

填空题已知f(x)=，则f(n)(3)=________．

填空题∫xdf"(x)=______．

填空题当a等于______时，函数，在(-∞，+∞)内连续．

填空题设a1，a2，…，am为正数(m≥2)，则

填空题设A是3阶矩阵，ξ 1 ，ξ 2 ，ξ 3 是三个线性无关的3维列向量，满足Aξ i =ξ i ，i=1，2，3，则A=________．

填空题设f(x)在积分区间上连续，则=______．

填空题设函数f(x)=在x=0处连续，则a=__________．设函数f(x)=在x=0处连续，则a=__________．

填空题函数的间断点的个数为______．

填空题Allmodernhumanoriginatedinsub-SaharanAfrica,accordingtoanewstudyboastedbyitsfoundersasthe"finalblow"againstanopposingviewpoint.Notsofast,saysoneanthropologistwhofindsflawsintheevidence.Thenewstudy,publishedintheJuly19issueofthejournalNature,deliverswhattheresearcherssaycouldbethefinalverdictinsupportofthesinglepoint"OutofAfrica"theory.Manicaandcolleaguestookmultiplemeasurementsofmorethan4,500malefossilskullsfrom105populationsaroundtheglobe.Theycombinedtheresultswithdatafromstudiesofglobalgeneticvariationsinhumans,findingthatbothgeneticandskullvariabilitydecreasedwithdistancefromAfrica.SopopulationsinsoutheasternAfricaheldthehighestvariabilitycomparedwithpopulationsinothercountries.Theresultsheldevenwhenthescientistsaccountedforclimate,sinceclimateconditionscanleadtochangesinskullfeatures."Inverycoldclimatesyoutendtogenerateaslightlythickerbrowridge.Whetherornotthat'stokeephorribleblizzardsoutofyoureyes,Idon'tknow,"Amossaid.Paststudiesbasedonskullmorphologyhavebeenweakandhavesupportedbothofthehumanoriginviews.Inhisownresearch,Hawksisfundingthatnaturalselectionhasledtochangesinthousandsofgenesduringonlythepastfewthousandyears."I'mreallythinkingjusttheoppositeofthispaper,"Hawkssaid."Therearedifferencesintheskullbetweenpopulations,includingtheirvariability,butitismostlyduetoveryrecenteffectsandnottheoriginofmodernhumans.""ThemuhiregionalideaisidenticaltotherecentAfricanoriginidea,exceptforitspredictionthatEuropeansandAsianswerepartofthesinglepopulationoforiginanddidn'tbecomeextinct."[A]"HumansseemtohavepouredoutofAfrica,spreadoutacrosstheworld,butatareallyquiteuniformratesuchthatyougetthislovelygraduallossofdiversity,"saidstudyteammemberWilliamAmosoftheUniversityofCambridge.[B]Allmodernhumansoriginatedfromthesameancestorsandtheykeptevolvingasthesocietyadvances.Somespeciesdiedoutbutothersremainedtoliveontheearth,whichisstillimpossibletosolve.[C]Attheendoftheday,aresolutiontothe"OutofAfrica"debatemaybeimpossible,hesaid.Mostoftheevidencecanbeinterpretedassupportingbothhuman-originstheories."It'sreallyhardtofindthetwo,"Hawkssaid.[D]Thisstudy"addsastronglineofevidencetotheOutofAfrica(hypothesis)usingsuchmorphology,"saidpaleontologistWillHarcourt-SmithoftheAmericanMuseumofNaturalHistoryinNewYork.Harcourt-Smithwasnotinvolvedinthecurrentresearch.[E]Debateovertheoriginsofmodernhumanshassimmeredamonganthropologistsforyears,withonetheoryassertingthatHomosapiensmigratedacrosstheworldfromasinglepointinAfrica.TheothertheorystatesthatmultiplepopulationsofHomosapiensindependentlyevolvedfromHomoerectusinregionsbeyondAfrica.[F]TherecentstudywasfundedbytheBiotechnologyandBiologicalSciencesResearchCouncil.Ithasprovidedconclusiveevidenceconcerningtheactualprocessofhumanevolution.[G]"Wehavecombinedourgeneticdatawithnewmeasurementsofalargesampleofskullstoshowdefinitelythatmodernhumansoriginatedfromasingleareainsub-SaharanAfrica,"saidleadresearcherAndreaManicaoftheUniversityofCambridge.41.______42.______43.______44.______45.______

填空题ylnxdx+xlnydy=0的通解是______．

填空题设A为三阶正交阵，且|A|＜0，|B-A|=-4，则|E-AB T |=______.

填空题微分方程满足的特解_______ 

填空题设y=y(x)由方程x2+xy2+2y=1确定，则dy=______．

填空题设z=xyyx，则________．

填空题 设阶可逆矩阵的每行元素之和为，则数__________一定是的特征值(为阶单位矩阵)

填空题设f(x)在(-∞，+∞)上可导，，又，则a=________．

填空题设z=(1+x2y)xy2，则