简介:一、填空题(12分)1.如果x2+ax+9=(x-3)2,则a=,5x2-3x+b=(5x+2)(x-1),则b=.2.当x时,分式-xx2+5的值是正数,当x=时,13-x=3.3.已知方程(a+3)x=3,当a时,方程有唯一解,当a时,它无解.4.已知等式2a-bn+a=n,当n≠2时,a=.5.方程1x+2-3+xx+2=0的增根是,化简4x2-14x2+4x-3=.6.计算1x+2-2x+5x+2=.二、选择题(15分)1.下列分解因式错误的是( ).(A)x4-8x2+16=(x+2)2(x-2)2(B)a4-1=(a2+1)(a+1)(a-1)(C)(a2+b2)2-4a2b2=(
简介:Inthispaperasimulatedannealing(SA)algorithmispresentedforthe0/1mul-tidimensionalknapsackproblem.Problem-specificknowledgeisincorporatedinthealgorithmdescriptionandevaluationofparametersinordertolookintotheperfor-manceoffinite-timeimplementationsofSA.ComputationalresultsshowthatSAper-formsmuchbetterthanageneticalgorithmintermsofsolutiontime,whilsthavingamodestlossofsolutionquality.
简介:ThispapershowsthattheC1-curvedfiniteelementdevelopedbyBernadoningeneralcannotsatisfytheessentialboundaryconditionsonapproximateboundary.Furthermore,amodifiedC1-curvedfiniteelementisgiven,whichiscompatiblewiththeelementofArgyristriangleandcansatisfythehomogeneousDirichletboundaryconditionsonapproximateboundary.
简介:Letf(x)∈C[-1,1],pn*(x)bethebestapproximationpolynomialofdegreentof(x).G.Iorentzconjecturedthatifforalln,p2n*(x)=p2n+1*(x),thenfiseven;andifp2n+1*(x)=p2n+2*(x),po*(z)=0,thenfisodd.Inthispaper,itisprovedthat,undertheL1-norm,theLorentzconjectureisvalidconditionally,i.e.if(i)(1-x2)f(x)canbeextendedtoanabsolutelyconvergentTehebyshevsories;(ii)foreveryn,f(x)-p2n+1*(x)hasexactly2n+2zeros(or,inthearcondsituation,f(x)-p2n+2*(x)hasexaetly2n+3zeros),thenLorentzconjectureisvalid.
简介:A.simplicialmesh(triangulation)isconstructedthatgeneralizesthetwo-dimensional4-directionmeshtoR~m.Thismesh,withsymmetric,shift-invariantvaluesatthevertices,isshowntoadmitaboundedC~1interpolantifandonlyifthealternatingsumofthevaluesattheverticesofany1-cubeiszero.Thisim-pliesthaiinterpolationattheverticesofanm-dimensional,simplicialmeshbyaC~1piecewisepolynomialofdegreem+1withonepiecepersimplexisunstable.
简介:SupposethatwewanttoapproximatefC[0,1]bypolynomialsinPn,usingonlyitsvaluesonXn={i/n,0≤i≤n}.ThiscanbedonebytheLagrangeinterpolantLnfortheclassicalBernsteinpolynomialBnf.But,whenntendstoinfinity,LnfdoesnotconvergetofingeneralandtheconvergenceofBnftofisveryslow.WedefineafamilyofoperatorsBkn,n≥k,whichareintermediateonesbetweenB(0)n=B1n=BnandBnn=Ln,andwestudysomeoftheirproperties.Inparticular,weproveaVoronovskaja-typetheoremwhichassertsthatBknf-f=0(n-[(k+2)/2)forfsufficientlyregular.Moreover,B(k)nfusesonlyvaluesofBnfanditsderivatiesandcanbecomputedbyDeCasteljauorsubdivisionalgorithms.
简介:性质awc1被许多作者使用由弱Chebyshevsubspaces的元素有关近似获得结果。在这份报纸,作者在细节学习这个性质,由收集有关它并且由发现新的散布结果。
简介:TwoestimatesusefulinapplicationsareprovedfortheFouriertransforminthespaceL2(X),whereXasymmetricspace,asappliedtosomeclassesoffunctionscharacterizedbyageneralizedmodulusofcontinuity.