Table Of ContentPartial Differential Equations
and Boundary Value Problems
with Maple
Second Edition
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Partial Differential Equations
and Boundary Value Problems
with Maple
Second Edition
George A. Articolo
AMSTERDAM•BOSTON•HEIDELBERG•LONDON
NEWYORK•OXFORD•PARIS•SANDIEGO
SANFRANCISCO•SINGAPORE•SYDNEY•TOKYO
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LibraryofCongressCataloging-in-PublicationData
Articolo,GeorgeA.
PartialdifferentialequationsandboundaryvalueproblemswithMaple/GeorgeA.Articolo.–2nded.
p.cm.
Includesbibliographicalreferencesandindex.
ISBN978-0-12-374732-7(pbk.:alk.paper)1.Differentialequations,Partial—Dataprocessing.
2.Boundaryvalueproblems—Dataprocessing.3.Maple(Computerfile)I.Title.
QA377.A822009
515’.3530285–dc22
2009010098
BritishLibraryCataloguing-in-PublicationData
AcataloguerecordforthisbookisavailablefromtheBritishLibrary.
ISBN:978-0-12-374732-7
ForinformationonallAcademicPresspublications
visitourWebsiteatwww.elsevierdirect.com
Typesetby:diacriTech,India.
PrintedintheUnitedStates
09 10 11 9 8 7 6 5 4 3 2 1
Contents
Preface............................................................................... ix
Chapter0:BasicReview...............................................................1
0.1 PreparationforMapleWorksheets...................................................... 1
0.2 PreparationforLinearAlgebra ......................................................... 4
0.3 PreparationforOrdinaryDifferentialEquations....................................... 8
0.4 PreparationforPartialDifferentialEquations.........................................10
Chapter1:OrdinaryLinearDifferentialEquations .................................. 13
1.1 Introduction.............................................................................13
1.2 First-OrderLinearDifferentialEquations.............................................14
1.3 First-OrderInitial-ValueProblem .....................................................19
1.4 Second-OrderLinearDifferentialEquationswithConstantCoefficients............23
1.5 Second-OrderLinearDifferentialEquationswithVariableCoefficients ............28
1.6 FindingaSecondBasisVectorbytheMethodofReductionofOrder...............32
1.7 TheMethodofVariationofParameters—Second-OrderGreen’sFunction.........36
1.8 Initial-ValueProblemforSecond-OrderDifferentialEquations .....................45
1.9 FrobeniusMethodofSeriesSolutionstoOrdinaryDifferentialEquations..........49
1.10 SeriesSineandCosineSolutionstotheEulerDifferentialEquation................51
1.11 FrobeniusSeriesSolutiontotheBesselDifferentialEquation.......................56
ChapterSummary ......................................................................63
Exercises................................................................................65
Chapter2:Sturm-LiouvilleEigenvalueProblemsandGeneralizedFourierSeries ..... 73
2.1 Introduction.............................................................................73
2.2 TheRegularSturm-LiouvilleEigenvalueProblem ...................................73
2.3 Green’sFormulaandtheStatementofOrthonormality ..............................75
2.4 TheGeneralizedFourierSeriesExpansion............................................81
2.5 ExamplesofRegularSturm-LiouvilleEigenvalueProblems ........................86
v
vi Contents
2.6 NonregularorSingularSturm-LiouvilleEigenvalueProblems.................... 129
ChapterSummary .................................................................... 146
Exercises.............................................................................. 147
Chapter3:TheDiffusionorHeatPartialDifferentialEquation.....................161
3.1 Introduction........................................................................... 161
3.2 One-DimensionalDiffusionOperatorinRectangularCoordinates................ 161
3.3 MethodofSeparationofVariablesfortheDiffusionEquation..................... 163
3.4 Sturm-LiouvilleProblemfortheDiffusionEquation............................... 165
3.5 InitialConditionsfortheDiffusionEquationinRectangularCoordinates ........ 168
3.6 ExampleDiffusionProblemsinRectangularCoordinates ......................... 170
3.7 VerificationofSolutions—Three-StepVerificationProcedure..................... 186
3.8 DiffusionEquationintheCylindricalCoordinateSystem ......................... 190
3.9 InitialConditionsfortheDiffusionEquationinCylindricalCoordinates......... 194
3.10 ExampleDiffusionProblemsinCylindricalCoordinates .......................... 196
ChapterSummary .................................................................... 205
Exercises.............................................................................. 206
Chapter4:TheWavePartialDifferentialEquation.................................217
4.1 Introduction........................................................................... 217
4.2 One-DimensionalWaveOperatorinRectangularCoordinates .................... 217
4.3 MethodofSeparationofVariablesfortheWaveEquation......................... 219
4.4 Sturm-LiouvilleProblemfortheWaveEquation ................................... 221
4.5 InitialConditionsfortheWaveEquationinRectangularCoordinates............. 224
4.6 ExampleWaveEquationProblemsinRectangularCoordinates................... 228
4.7 WaveEquationintheCylindricalCoordinateSystem.............................. 244
4.8 InitialConditionsfortheWaveEquationinCylindricalCoordinates ............. 249
4.9 ExampleWaveEquationProblemsinCylindricalCoordinates.................... 251
ChapterSummary .................................................................... 261
Exercises.............................................................................. 262
Chapter5:TheLaplacePartialDifferentialEquation...............................275
5.1 Introduction........................................................................... 275
5.2 LaplaceEquationintheRectangularCoordinateSystem .......................... 276
5.3 Sturm-LiouvilleProblemfortheLaplaceEquationinRectangular
Coordinates............................................................................ 278
5.4 ExampleLaplaceProblemsintheRectangularCoordinateSystem ............... 284
5.5 LaplaceEquationinCylindricalCoordinates....................................... 299
5.6 Sturm-LiouvilleProblemfortheLaplaceEquationinCylindrical
Coordinates............................................................................ 301
Contents vii
5.7 ExampleLaplaceProblemsintheCylindricalCoordinateSystem ................ 307
ChapterSummary .................................................................... 325
Exercises.............................................................................. 327
Chapter6:TheDiffusionEquationinTwoSpatialDimensions......................339
6.1 Introduction........................................................................... 339
6.2 Two-DimensionalDiffusionOperatorinRectangularCoordinates................ 339
6.3 MethodofSeparationofVariablesfortheDiffusionEquationin
TwoDimensions ...................................................................... 341
6.4 Sturm-LiouvilleProblemfortheDiffusionEquationinTwoDimensions ........ 342
6.5 InitialConditionsfortheDiffusionEquationinRectangularCoordinates ........ 347
6.6 ExampleDiffusionProblemsinRectangularCoordinates ......................... 351
6.7 DiffusionEquationintheCylindricalCoordinateSystem ......................... 365
6.8 InitialConditionsfortheDiffusionEquationinCylindricalCoordinates......... 371
6.9 ExampleDiffusionProblemsinCylindricalCoordinates .......................... 374
ChapterSummary .................................................................... 394
Exercises.............................................................................. 395
Chapter7:TheWaveEquationinTwoSpatialDimensions..........................409
7.1 Introduction........................................................................... 409
7.2 Two-DimensionalWaveOperatorinRectangularCoordinates .................... 409
7.3 MethodofSeparationofVariablesfortheWaveEquation..........................411
7.4 Sturm-LiouvilleProblemfortheWaveEquationinTwoDimensions............. 412
7.5 InitialConditionsfortheWaveEquationinRectangularCoordinates............. 417
7.6 ExampleWaveEquationProblemsinRectangularCoordinates................... 420
7.7 WaveEquationintheCylindricalCoordinateSystem.............................. 437
7.8 InitialConditionsfortheWaveEquationinCylindricalCoordinates ............. 443
7.9 ExampleWaveEquationProblemsinCylindricalCoordinates.................... 447
ChapterSummary .................................................................... 466
Exercises.............................................................................. 467
Chapter8:NonhomogeneousPartialDifferentialEquations ........................477
8.1 Introduction........................................................................... 477
8.2 NonhomogeneousDiffusionorHeatEquation...................................... 477
8.3 InitialConditionConsiderationsfortheNonhomogeneousHeatEquation ....... 488
8.4 ExampleNonhomogeneousProblemsfortheDiffusionEquation................. 490
8.5 NonhomogeneousWaveEquation................................................... 510
8.6 InitialConditionConsiderationsfortheNonhomogeneousWaveEquation ...... 520
8.7 ExampleNonhomogeneousProblemsfortheWaveEquation ..................... 523
ChapterSummary .................................................................... 546
Exercises.............................................................................. 547
viii Contents
Chapter9:InfiniteandSemi-infiniteSpatialDomains...............................557
9.1 Introduction........................................................................... 557
9.2 FourierIntegral....................................................................... 557
9.3 FourierSineandCosineIntegrals ................................................... 561
9.4 NonhomogeneousDiffusionEquationoverInfiniteDomains ..................... 564
9.5 ConvolutionIntegralSolutionfortheDiffusionEquation ......................... 568
9.6 NonhomogeneousDiffusionEquationoverSemi-infiniteDomains............... 570
9.7 ExampleDiffusionProblemsoverInfiniteandSemi-infiniteDomains ........... 573
9.8 NonhomogeneousWaveEquationoverInfiniteDomains.......................... 586
9.9 WaveEquationoverSemi-infiniteDomains ........................................ 588
9.10 ExampleWaveEquationProblemsoverInfiniteandSemi-infiniteDomains ..... 594
9.11 LaplaceEquationoverInfiniteandSemi-infiniteDomains ........................ 606
9.12 ExampleLaplaceEquationoverInfiniteandSemi-infiniteDomains.............. 612
ChapterSummary .................................................................... 619
Exercises.............................................................................. 621
Chapter10:LaplaceTransformMethodsforPartialDifferentialEquations.........639
10.1 Introduction........................................................................... 639
10.2 LaplaceTransformOperator......................................................... 639
10.3 InverseTransformandConvolutionIntegral........................................ 641
10.4 LaplaceTransformProceduresontheDiffusionEquation......................... 642
10.5 ExampleLaplaceTransformProblemsfortheDiffusionEquation................ 646
10.6 LaplaceTransformProceduresontheWaveEquation ............................. 666
10.7 ExampleLaplaceTransformProblemsfortheWaveEquation .................... 671
ChapterSummary .................................................................... 693
Exercises.............................................................................. 694
References..........................................................................709
Index ...............................................................................711
Preface
ThisisthesecondeditionofthetextPartialDifferentialEquationsandBoundaryValue
ProblemswithMaple,AcademicPress,1998.ThetexthasbeenupdatedfromMaplerelease4
torelease12.Inaddition,basedonrecommendationsandsuggestionsofthemanyhelpful
reviewersofthefirstedition,thetextincorporatesmoreofthemacrocommandsinMapletobe
usedasameansofcheckingsolutions.Similartowhatwasdoneinthefirstedition,Icontinued
thepresentationofthesolutionstoproblemsusingthetraditional,fundamental,mathematical
approachsothatthestudentgetsafirmunderstandingofthemathematicalbasisofthe
developmentofthesolutions.Themacrocommandsarenotintendedtobeusedasameansof
teachingthemathematics—theyareusedonlyasaquickmeansofchecking.
Ifthereeverweretobeaperfectunionincomputationalmathematics,onebetweenpartial
differentialequationsandpowerfulsoftware,Maplewouldbeclosetoit.Thistextisan
attempttojointhetwotogether.
Manyyearsago,Irecallsittinginapartialdifferentialequationsclasswhentheprofessorwas
discussingaheat-flowboundaryvalueproblem.Usingapieceofchalkattheblackboard,he
wasmakingaseeminglydesperateattempttogethisstudentstovisualizethespatial-time
developmentofthethree-dimensionalsurfacetemperatureofaplatethatwasallowedtocool
downtoasurroundingequilibriumtemperature.Youcanimaginethefrustrationthathe,and
manyprofessorsbeforehim,experiencedatdoingthistask.Now,withthepowerful
computationaltoolsandgraphicscapabilitiesathand,thiseraofdifficultyisover.
Thistextpresentstheformalmathematicalconceptsneededtodevelopsolutionstoboundary
valueproblems,anditdemonstratesthecapabilitiesofMaplesoftwareasbeingapowerful
computationaltool.Thegraphicsandanimationcommandsallowforaccuratevisualizationof
thespatial-timedevelopmentofthesolutionsonthecomputerscreen—whatstudentscould
onlyimaginemanyyearsagocannowbeviewedinrealtime.
Thetextistargetedforusebysenior-graduatelevelstudentsandpractitionersinthedisciplines
ofphysics,mathematics,andengineering.Typically,thesepeoplehavealreadyhadsome
exposuretocoursesinbasicphysics,calculus,linearalgebra,andordinarydifferential
equations.TheneedforpreviousexposuretotheMaplesoftwareisnotnecessary.InChapter0,
weprovideanintroductiontosomesimpleMaplecommands,whichisallthatisnecessaryfor
ix