如图，公园有一块边长为2的等边△ABC的边角地，现修成草坪，图中DE把草坪分成面积相等的两部分，D在AB上

Question

如图，公园有一块边长为2的等边△ABC的边角地，现修成草坪，图中DE把草坪分成面积相等的两部分，D在AB上，E在AC上．（1）设AD=x（x≥0），ED=y，求用x表示y的函数关系式；（2）如果DE是灌溉水管，为节约成本，希望它最短，DE的位置应在哪里？如果DE是参观线路，则希望它最长，DE的位置又应在哪里？请予证明．

Answer 1

In the information society, the enterprise only has uses each advancedmanagement way and the technical method realization information highintegration, enhances the gain information, the analysis informationand the use information ability, the development knowledge economy,can gain the superiority in the intense market competition, along withmarket economy development. various professions in order to strengthenthe information management, enhance the economic efficiency therequest, is urgent needs to apply the modernization informationprocessing technology in the economy supervisory work. Rapidly develops hotel profession. in order to raise own managementlevel. to strengthen the competitive ability, enhances the economicefficiency and so on, needs dynamic to grasp in hotel each link theinformation change. inevitably not to be able to leave the computerhelp. This article elaborated the analysis, the development, has designed ahotel onstage management system management system the process. Thissystem unified modernized, the science hotel management thought, thekey analysis has designed the hotel onstage revolution service flow,realized has prearranged the management, enters the management, theexpense keeps accounts, to receive the silver to return a house modulethe and so on management, room condition management, systemmaintenance function, like to guest room information, customerinformation, room condition establishment as well as operatorjurisdiction inquiry and revision. Greatly enhanced its workingefficiency. The system by Microsoft SQL Server 2,000 took the backstage database,PowerBuilder9.0 is the onstage development kit, the utilization chasesthe level decomposition from the top the modulation structural designthought, the object-oriented design method, has completed the hotelmanagement information system main module. Key word: The hotel management system management system, returns ahouse receives the silver, the window inherits