最新3.2.2-函数模型的应用举例-课件(人教A必修1)幻灯片

3.2.2-函数模型的应用举例-课件(人教A必修1) 典题例证技法归纳题型一 二次函数模型的应用据市场分析，烟台某海鲜加工公司，当月产量在10吨至25吨时，月生产总成本y(万元)可以看成月产量x(吨)的二次函数；当月产量为10吨时，月总成本为20万元；当月产量为15吨时，月总成本最低为17.5万元，且为二次函数的顶点．例1题型探究 (1)写出月总成本y(万元)关于月产量x(吨)的函数关系；(2)已知该产品销售价为每吨1.6万元，那么月产量为多少时，可获最大利润？ 变式训练 例2 t(天)5152030Q(件)35252010(1)根据图1，写出该产品每件销售价格P与时间t的函数关系式；(2)在所给的直角坐标系(图2)中，根据表中提供的数据描出实数对(t，Q)的对应点，并确定日销量Q与时间t的一个函数关系式；(3)在这30天内，哪一天的日销售金额最大？(日销售金额＝每件产品销售价格×日销量) 因此日销售量Q与时间t的一个关系式为Q＝－t＋40(00)，哪个模型能更好地反映该公司年销量y与第x年的关系？ 3．芦荟是一种经济价值很高的观赏、食用植物，不仅可以美化居室、净化空气，还可美容保健，因此深受人们欢迎，在国内占有很大的市场，某人准备进入芦荟市场，栽培芦荟，为了了解行情，他进入市场调研，从4月1日起，芦荟的种植成本Q(单位：元/10kg)与上市时间t(单位：天)的数据情况如下表：变式训练 (1)根据上表数据，从下列函数中选取一个最能反映芦荟种植成本Q与上市时间t的变化关系：Q＝at＋b；Q＝at2＋bt＋c；Q＝a·bt；Q＝alogbt；(2)利用你选择的函数，求芦荟种植成本最低时上市天数t及最低种植成本？时间t50110250种植成本Q150108150 解：(1)由所提供的数据知，反映芦荟种植成本Q与上市时间t的变化关系不可能是常数函数，故用上述四个函数中任意一个来反映时都应有a≠0，而函数Q＝at＋b，Q＝a·bt，Q＝alogbt均为单调函数，这与表格所给数据不符合，所以应选择二次函数y＝at2＋bt＋c，将上述表格 通过研究学生的学习行为，心理学家发现，学生接受能力依赖于老师引入概念和描述问题所用的时间．讲座开始时，学生的兴趣激增，中间有一段不太长的时间，学生的兴趣保持较理想的状态，随后学生的注意力开始分散，分析结果和实验表明，用f(x)表示学生掌握和接受概念的能力(f(x)值越大，表示接受的能力越强)，x表示提出和讲授概念的时间(单位：min)，可有以下的公式：备选例题 (2)开讲后5min与开讲后20min比较，学生的接受能力何时强一些？(3)一个数学难题，需要55的接受能力以及13min时间，老师能否及时在学生一直达到所需接受能力的状态下讲授完这个难题？ 方法感悟 知能演练轻松闯关 本部分内容讲解结束按ESC键退出全屏播放 YoungGoodmanBrown NathanielHawthorneHewasborninSalem,Massachusetts.SomeofhisancestorsweremenofprominenceinthePuritanTheocracyof17thcenturyNewEngland.YoungHawthornewasintenselyawareofthemisdeedsofhisPuritanancestors,andthisawarenessledtohisunderstandingofevilbeingatthecoreofhumanlife,to“theblacknessinHawthorne”,asHermanMelvilleputit.Hawthornewrotesomebooksasanattemptatexpiatingthesinofhisancestors. Readinghistalesandromances,onecannotbutbeoverwhelmedbythe“black”visionwhichtheseworksreveal.ItillustratestosomeextenttheinfluencethattheCalvinistdoctrineof“originalsinandtotaldepravityhaduponhismind. PlotYoungGoodmanBrownbeganhisstoryatsunsetinSalem,Massachusetts,leavinghisyoungwifeFaithtojoininanunspecifiedbutobviouslyunholyritual.HemetmanypeoplealongthewayandmanyofthemwerehistownfolkwhomhehadconsideredexemplaryChristians,includinghisminister,deacon,thewomanwhotaughthimcatechismandevenhisvirginwife. Theceremonybegansomewheredarkanddeepinsidetheforest.Thenextmorning,BrowncameslowlyintothestreetofSalemwherehebumpedintothepeoplehehadmetalongthewaytotheritual.Deeplyshakenbywhathehadseen,Brownbegantoholdasuspiciousandcynicalattitudetowardthemincludinghiswife. Tosumup,thestorytellBrown’scollapseofFaith. SymbolsSunsetPinkribbonsForestFaithGoodmanBrownThesnakelikestickSalem SunsetAsweknow,thestoryhappenedatsunsetwiththedevelopmentatnight.Sunsetisthesarting-pointofnightwhichsignifiesecilandarisepeople’sfearofunknown.Theauthorchosesuchatimeforthepurposeofbuildinguphorrificatmosphereandwhat’smore,ofdemonstratingthedarksideofthenatureofhumanbeings. PinkRibbonsAccordingtoBible,redrepresentsevilwhilewhiterepresentsholiness.Andthecolorofribbonsispink-betweenredandwhite.OtonlydothepinkribbonsrepresentweosidesofFaith-purityandkindnessasawifeandevilaasonewhojoinedinsucharitual,butalsorepresentBrown’sreligiousbelief. Atthebeginningofthestory,Faithwhoworesuchacaptrieddetainherhusband,whichalsomeantVrowntriedtotemporallyabnegatehisreligiousbelieftoleavefortheevilparty. FaithThisnameisrepeatedthroughoutthewholestory.Atthebeginningofthestory,Brownputhisheadback,aftercrossingthethreshold,toexchangeapartingkisswithhisyoungwife.AndFaith,asthewifewasaptlynamed… Andwhenheenteredtheforestandmetthecompanion,hesaid”Faithkeptmebackawhile.” Faithiscomprehendedintwoways.OnewayisthattherecentlymarriedwifeFaithBegrudginglylethimjointheritualandtheotheroneisthatVrown’sreligiousbeliefmadehimhesitatedbeforehisdeparture. ThestoryhappensinSlemvillagewhereandwhennecromancywasverypopular.Atthattime,peoplefromofficialstocommononeswereallcaptivatedbynecromancy.Bysettingthehistoricalbackgroundof“Salemwitchtrals”,writersuccessfullyprovidedthereaderswithasenseofrealityandlettehmbelievethatthestorymighthavebeendericedfomwhathadreallyhappenedbefore,thuspulledhisstorytothemnearerandmadethemmoredevoted. YoungGoodmanBrownItisveryintelligentofHawthornetochoosethisnameasitisapun.Itrevealsaimagetousthattheheroisayouthfulmanofvirtue.Plus,Brownisapopularnameasitcanrepresent“Everyman”. TheSnake-likeStickWhenBrownwalkedinthedarkforest,hemetanoldmanwhocameoutsuddenlywithastick“whichborethelikenessofagreatblacksnake,socuriouslywroughtthatitmightalmostbeseentotwistandwriggleitselflikealivingserpent.”TheserpentstickmakesusthinkoftheimageofSatanintheBible.Itsymbolizesevilseduction. Forest“…adearyroaddarkenedbyallthegloomiesttreesoftheforest,whichbarelystoodasidetoletthenarrowpathcreepthrough,andclosedimmediatelybehind.Itwasallaslonelyascouldbe…”“theremaybeadevilishIndianbehindeverytree” Theforestsymbolizesthedarkevilforce,whichindicatesman’sfearfulnaturetowardsthemysteriousandtheunknown. ThemeThestoryuncoverstheinherentevilandsinofhumanity.HawthornehadsetalastingecampleinAmericanLiteratureofcombiningmoraldiscussionwithhighlyartisticrepresentationjustaswecanseefromthisstory.HawthorneusedBrown’sexperiencetoenlightenpeopletobebraveandfacealltheevilinlifewithanopen HawthorneusedBrown’sexperiencetoenlightenpeopletobebraveandfacealltheevilinlifewithanopenheart,sothatonecouldgrowupinahealthywayandbecomemorematureandgivepositivemeaningtolife,sothatpeoplecouldavoidBrown-destroying. TheConclusionThePuritanismitselfasauniquehistoricalphenomenonplaysasignificantroleinthedevelopingofAmericanliterature.ThroughtHawthorne’scomplex,contradictoryreligiousviews,thethemeofhisdepravityofthePuritanismandthe“orginalsin”,alsoitreflectedthatthepruitansuppressanddestructtothehumanbeings.Thiswasaspecialnesswithwhichhisfamilyandsocialbackgroundwasinseparable.