新课标人教版课件系列《高中英语》必修5-1
1ReadingTask(P45)FindingTheSolutionPuzzleABCAABBCCDDECanyougooveritwithoutmissinganypointsorgoingoveralinetwice
FABCAABBCCDDEstartfinishFABCAABBCCDDEEulersaid,“Ifafigurehasmorethantwooddpoints,youcannotgooveritwithoutliftingyourpencilfromthepageorgoingoveralinetwice
C:evenpointsA
B:evenpointsC
D:oddpointsC
F:oddpointsA
B:evenpointsFLeonhardEuler(1707-1783)Born:15April1707inBasel,SwitzerlandDied:18Sept1783inStPetersburg,RussiaEulerwasafamousmathematicianintheeighteenthcentury,heintroducedanewbranchofmathematicscalledtopology
Itisaformofgeometrythathelpyouunderstandthingsbyturningthemintodiagrams
ReadingP45WhatisEulerpath
curvedlinestraightlineevenpointoddpointA,B,CD:oddpointsA,C:oddpointsB,D:evenpointsNoEulerpathHasEulerpathstartfinishFig4:A1234Figure4