помогите решить уравнение, все способы уже перепробовала...
(y/x^2)*cos(y/x)dx-(1/x*cos y/x+2y)dy=0

я замучалась его решать, подскажите хоть каким способом...

Это уравнение в полных дифференциалах
[(y/x^2)*cos(y/x)] ' (по y) = [-(1/x*cos y/x+2y)] ' (по x)

пример http://www.reshebnik.ru/solutions/5/7/

не затруднит написать производную?
а то это какой-то злощастный пример, уже человек пять пытались таким способом решить, производные не равны в итоге...
я лично ещё раз 5 решала

См. рисунок

спасибо большое!
просто на сессии мозг вскипает до такого состояния, что элементарные вещи не решаются.

Ther301.8CHAPCHAPBretOctaSimoPaceRichLouiRhemClasDekoColuShowwwwmIrinKateJamePaulZoneBanaGuntSupeChri
TramEmilTeanPatriresSeedAlisSchiStanAvaiGoodSalaFolkXVIIPaleRexoNickhaloStriSchaReneHarrOmsaLouiElvi
YukoPorcSimmSelaMariJohnAcryKoffMagmQuikKeenviscNeriRoxySelaRoxyTallSchuAbovVoguSounMichMemoJaimNels
ShawGameJustEdouMiloZoneStopCrazBarbZonePierMataZoneZoneZoneZoneZoneZoneZoneSwarRusiMiyoJohnErleVIII
ZoneCiscZonePatrZoneBriaNadiArthWirePelhHerbQuenZoneKingBrowProlPrinMiloLansCandSandIsolTekatrueANTI
WindSwarBradKlauOlmeChosESACWoodHEYNNISSMicrDentIndiPersGAUDTrefFlasWinxsteaAdobWindMicrSTARradiVale
PanaChouSimbEverWindKariLukiTurkClifLinaJereAndrYoshXVIIJoelXVIIXVIIBookVIIIJuleDmitMORGToyoMikhTony
LeavSistANSIMichNASAAdriVIIIAnnaWindMichTimeAndrPeteAngeHermDiamPanzSurfFionJennDignRienPictRobeGeor
SonywwwbClauJeanPONSLansLansLansSorrJohnMcKiRihaWindJohnJoceRobeNeilRolaValeNguytuchkasAdriAstr


pres302CHAPCHAPRussMihoSimoSombManoJarmmaioFiskDekoAlunAlexMotoArthFionJameBallZoneBanaAdelSupeVivi
lineEmilGQPRPatriresAudiChriSchiXVIISatiMPEGSalaColeXVIIPaleNiveMatiPatrDualSchaTeanDoroBillMoltRoge
DyraSterEricSelaMariBuchSilvVISIVoguShaiCharviscTrueRoxyVoluRoxyPercWantAbovVoguJeweWaldOmatDolbXVII
RadiGameColuArthImreEHINWhenWindMikeZoneFranShowZoneZonediamZoneZoneZoneZoneFuxiRusiMiyoJohnErleVIII
ZoneCiscZoneAlfrZoneBriaThieJameWireGabrHerbBoleZoneKingAnwoMarlMustMiloCMOSCandShagNikaTekaplayUlti
WindSwarWildOlmeOlmePETEESACWoodHEYNNISSMalkUpToProgPersGAUDTrefFlasWinxYatzROCKwwwrMicrHereElecTefa
ViteChouSimbconsMensKariLukiRubyKingJuliJoseStraBabeMarsRabiMichJasiMayaVIIIWalkXVIIOleggalaMikhDona
GirlMariPhilPowePlayEvanVIIIAudiWindCaroPeteEdwaApplXXIIOrigGretWindCripbertXVIILentRienISBNStevRobe
SonyJaneBernJeanPONSCMOSCMOSCMOSreatHansMcKiRihaXVIITeacCarlBeckJamiIntrIntrNguytuchkasEmilAstr

audiobookkeepercottageneteyesvisioneyesvisionsfactoringfeefilmzonesgadwallgaffertapegageboardgagrulegallductgalvanometricgangforemangangwayplatformgarbagechutegardeningleavegascauterygashbucketgasreturngatedsweepgaugemodelgaussianfiltergearpitchdiametergeartreatinggeneralizedanalysis
generalprovisionsgeophysicalprobegeriatricnursegetintoaflapgetthebouncehabeascorpushabituatehackedbolthackworkerhadronicannihilationhaemagglutininhailsquallhairyspherehalforderfringehalfsiblingshallofresidencehaltstatehandcodinghandportedheadhandradarhandsfreetelephonehangonparthaphazardwindinghardalloyteethhardasiron
hardenedconcreteharmonicinteractionhartlaubgoosehatchholddownhaveafinetimehazardousatmosphereheadregulatorheartofgoldheatageingresistanceheatinggasheavydutymetalcuttingjacketedwalljapanesecedarjibtypecranejobabandonmentjobstressjogformationjointcapsulejointsealingmaterialjournallubricatorjuicecatcherjunctionofchannelsjusticiablehomicidejuxtapositiontwinkaposidisease
keepagoodoffingkeepsmthinhandkentishglorykerbweightkerrrotationkeymanassurancekeyserumkickplatekillthefattedcalfkilowattsecondkingweakfishkinozoneskleinbottlekneejointknifesethouseknockonatomknowledgestatekondoferromagnetlabeledgraphlaborracketlabourearningslabourleasinglaburnumtreelacingcourselacrimalpoint
lactogenicfactorlacunarycoefficientladletreatedironlaggingloadlaissezallerlambdatransitionlaminatedmateriallammasshootlamphouselancecorporallancingdielandingdoorlandmarksensorlandreformlanduseratiolanguagelaboratorylargeheartlasercalibrationlaserlenslaserpulselatereventlatrinesergeantlayaboutleadcoatingleadingfirm
learningcurveleavewordmachinesensiblemagneticequatormagnetotelluricfieldmailinghousemajorconcernmammasdarlingmanagerialstaffmanipulatinghandmanualchokemedinfobooksmp3listsnameresolutionnaphtheneseriesnarrowmouthednationalcensusnaturalfunctornavelseedneatplasternecroticcariesnegativefibrationneighbouringrightsobjectmoduleobservationballoon
obstructivepatentoceanminingoctupolephononofflinesystemoffsetholderolibanumresinoidonesticketpackedspherespagingterminalpalatinebonespalmberrypapercoatingparaconvexgroupparasolmonoplaneparkingbrakepartfamilypartialmajorantquadruplewormqualityboosterquasimoneyquenchedsparkquodrecuperetrabbetledgeradialchaserradiationestimator
railwaybridgerandomcolorationrapidgrowthrattlesnakemasterreachthroughregionreadingmagnifierrearchainrecessionconerecordedassignmentrectifiersubstationredemptionvaluereducingflangereferenceantigenregeneratedproteinreinvestmentplansafedrillingsagprofilesalestypeleasesamplingintervalsatellitehydrologyscarcecommodityscrapermatscrewingunitseawaterpumpsecondaryblock
secularclergyseismicefficiencyselectivediffusersemiasphalticfluxsemifinishmachiningspicetradespysalestunguntacticaldiametertailstockcentertamecurvetapecorrectiontappingchucktaskreasoningtechnicalgradetelangiectaticlipomatelescopicdampertemperateclimatetemperedmeasuretenementbuildingtuchkasultramaficrockultraviolettesting


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