Ho Thi Mai Phuang Tap chi KHOA HOC & CONG NGHE KHAI T H A C L O I G I A I B A I T A P T O A N G O P P H A N B O I D U O N G C H O H O C S I N H \ I O T S O V E U T O C U A PII A M C H A T T R I T U F[.]
Ho Thi Mai Phuang Tap chi KHOA HOC & CONG NGHE KHAI T H A C LOI GIAI BAI T A P T O A N G O P P H A N B O I D U O N G C H O H O C S I N H \ I O T S O V E U T O C U A PII.A.M C H A T T R I T U F H6 Thi Mai Phuong' Trucmg Dai hoc Sir pham - DH Thai \gu\ en TOM T A ' I Pham chat tri tuc la mot Irong nhung yeu 16 can ihiei cho hoc tap de tiep thu In ihiic ren luyen kT nang dap irng dugc nhirng yeu cau cua cuoc song Bai tap loan hoc la mot noi dung co nhieu co hoi de boi duang va hinh cho hpc smh nhirng yeu to ciia pham chat tn tue Trong day hoc giai bai tap loan neu giao vien biet each huong dan hoc sinh phan tich bai loan, biet nhm cac yeu 16 da cho nhOng moi hen he khae biet khai thac tim duac nhieu lai giai cho moi bai loan se giiip hoc smh linh hoat doc lap, tu duoc phat tnen phat hien van de moi tim huong di moi, tao ket qua moi, Nhirng hoat dong gop phan boi duong pham chat iri tue cho hoc smh nham nang cao hieu qua cua day va hoc Til' khoa; khai thdc ldi gtai bdi ldp todn, bdi ducrng mdl sdyeu id cua phdm chat tri tue DAT V A N DF, cac yeu to cua PCI" I phai ttu'oc lien hanh Rtii d u o n s va ren luven cho HS phSm ch^t tri '^^^ ^1^'^^' '^'^^ ^^'^ trinh day hgc dac biet la iuc (PCTT) la mot nhiem vu c^n ihigt day hoc khai thac Itii giai cua bai lap lOiin, diiy hoc ttian Giai loan la hinh thuc chu yeu NHU'NG YEU T O C O BAN CUA PCTT cua hoat dong hpc loan, cac bai tap loan viia Viec bdi dudng cae yen to co ban cua P C l f lii muc dich la p h u o n g lien eo hieu qua va khong the thay the viec giiip nguoi hoc n.^m virng Ui thiic ren luyen kT nang, thong qua khai Ihac I61 giai bai tiip loiin ciiii dua tren nhiing tu tuong chu dao sau + Q.',^^ ^i^^ ^1,^,3,, j^,^;,^ ,|„',^ i^i „,-i,5^ ,.^1;, Day loiin ht.ie pluil hoc loan tluic chat la day hoat dting (HD) hgc nham tich cue luia I ID hoc tiip cua smh (HS) HS la ehu tht- eua HD hoc diKTc cuon luil viio n h u n e I ID hoc lap, tu c h u o n g trinh THCS luen iuinli , j-,^^,,^ |^^-,., ,|^^^, ^,,,^1^ 1^^,,-.,^^ ^^^., ,^^^, p|^„,„^„ ^i^.^ ^^^^^ |,^^^ ^.^^^ ^^^^ 1^^^^ ,^^,^,, ^-^^^^ 1,^^^ ^-^^ ,„ lue kham pha kicn thirc, Giao vien (GV) la ngiroi thiet ke, tti chiic va chi dao HD hoc tap Mtil lron^ nhiing muc dich dav hoc Toan o theo nhiing dinh hirting phiin lich, king hgp irudng thong la giiip HS phal trifiii niing ^iic du kit:ii eo ban bai toiin luc va icn luyen cac phiim chat iri lue ren + Khai tluic I61 giiii bai tap toiin phu hap voi luyt:ii III logic vii ngon ngu chinh \iic dtii tuong HS de dat duoc nhung yeu ciiii co phiil trien kha niing suy doan va luong tuong, ban vc kien thue kT nang nham htii duiing Khai thiic Itii giai biii Ifip loan plu ren luyen nhu'ng IID tri tue co biin ya hinh nhimg veu tti cua PCTT thiinh nhiing PCTT, Trong giiii lOiin, tiutSc lien phai bicl nhin bai toiin nuil cich khiii qiiiil, phiin lich ciii da eho va ciii can lim dc ihiiy dime mtii lit:n he giua cluing Sau dti dua vao Ciic kicui thiic dii ITnh hoi HS viui dung linh luiat, dgc liip de lim d u a c cac ldi giai khiic cua biii loan, lim liri giai luiy nhal Siing liio nhat, Vi viiy, vice htii duting ^^^ Titih^lmh h o a i cua tri tue • /„; ,u,i< ,-,„ini7 ,•„.„./ ; / nri.^r,4,> „„nl.nm riini li hoe clio rang, tinh Imh hoai cua Iri Uu du'oc bit}ii luen *) Kha niing ihiiy doi phutuig huting giai quyel van de plui hop vtii sir ihay diii cua ciic dieu kien, biet tim phuong luiong mtii de nghien ciiu va giai qiiyC-i \dn de, kluic pluic duii dti diip kluitin llict) m.iii dnih siin, m,i\ "Hic chtiug liiih > CIM lu I Id Thi Mai Phuons Tap chi KHOA HOC & CONG NGHE ") Kha nang nhin nhan mgt van de mot hien tirong duoi nhieu khia canh hay goc quan diem khac nhau, *) Kha nang xac lap su phu thuoc ciia cac kien thirc theo mgl trat tu ngugc vai each da biet (tinh thuan nghich cua qua trinh tu' duy), Trong qua trinh khai ihac de tim toi nhieu loi giai cho mgl bai loan HS phai van dung cac kien thirc von cd va tu linh boat de phan tich vice giai loan doi la sir mo mam du doan tii lim duong ngan nhat, Su tim toi khai thac tim nhieu I6"i giai cho bai toiiii cung phan anh dugc nhung yeu to linh hoat doc lap va sang tao ctia tu linh linh hoat la pham dial can thiet doi vai HS giai loan, no guip cho HS co kha niing thay doi phuong hii'ii"ng giai quyel van tie lim la huong di moi de dang chuyen tir boat dting ll i tue (I IDTT) niiy sang HDTT khac, Tinh doc lap linh dgc lap cua tu the hien a kha nang lu minh nhin tha; van dc phai giai quyet, Ur minh lim loi giai dap cho van de do, Ngoai r;i tinh dgc lap lien he mat thiet voi tinh phe pluin eiia lu duy, Btii dining kha nang IID tu dtic lap cho IIS de ehicm lIiili kien thuc la each hicu qua nluit dc Ciic em hieu duoc kicn thuc mot each •liiu ^i.ic Vii cti y tluic inh dpc liip cua HS bieu bien a kha nang titic lap suy nghT, biel each to chiic cong v iec cua minh mtit Ciicli hap li duoi su huong dan giiip dti'cua GV Tinh Min(l XZve/i r 2r-(v i2\-i.f 3-|,r+2i)4\-+2i| -l^(.r+2tJ4i; => v" + 2.V - «= (-V + 1)" = o ) mot nuhieni la Va> phuong trinh dii c^-1 jV.ve/f | ( v ' - l v ) ' + ( v - + v ) + 6=;() (11 Vc trai ciia ( I ) \uat hien nlian tu chung •'+2.V Dal V ^ -1 (nghiem kep) Ciing \ i huong phan tfch nhu lien, neu nhin nhiin linh hoat hicu (hue duoi d^ii can l;T lam Ihuc bac : IIS co ihO lach v'+2.Y-3= (3 V v ) + de CO loi giai khiTc cho bai tt^aii X +2\ = t thi phuong trinii (1) I a CO Ihanh phuong trinll bac an t 73-.V 2.V .V +2.v( l +11+ h- < o i Y - x -2Y -(3 Dill v"3-.v Vni / = - ! : : : > v't2v=-lt>.i-'+2v+l=0o(.v+l)"- ()< >.v=-l (nghicin kep) 2v=/ I -2.VI + (."ll / > | thi phuong trinh (3) tro Ihanlr / - -C + c^r +t- = l)c >-^ \oi / = - - > \-'ilv^-6»r-i2v4 ( I < > ( T - I | 45 = (\o nghiem) Nen phirong trinh d.a cho co nghiein la V ^ •1 \ e i i hep tiic nhin nhan cac \ c i i to o hai \ e cua I ' I IIS phan lich \i\ nhan thav bieu lliuc h-x'-lx ^J•'3- ( V - + v ) Khi hai < o ( v + l)" =(1.V\',i> mghicmkcpl pluioiie Innh da cho co moi iiglucni ^ -\ \e Ciia phirong trinh co chung bicu dure \ i^.^- nhin nhan ^.i, du kien clio iroin.; bai (v'+2vl o nhung goc nhm khac iili.iu deu dua pin nen dat v" l - l = ( dc dua >c Hd Thi Mai Phuong Tap ehi KHOA HOC & CONG NGHR irinh da cho vc dang x ' + x + l = hudng HS den viee phan tich hai vc ciia PT de cung xuat hien bieu thuc chung (x + l)" de tiiu each tliai khac I a co; Vay phirting trinh da cho c6 mgt nghiem Y I ~ Nhu vay bang viec dat an phu tuang tir ta dira dugc PT ve he phuong trinh hai an biet each giai V3 - -V - 2.V - x~ + 2.V + > v / ^ x + \)- =(.v + l)- + Dat (.v + l ) - = / (4)tra Dat (4) { / > ) thi phirtTng uinh 114(14): 109- 113 v3-.v" -2.V = II [x~ + 2.V + = V (;/ v > ) ta CO he phuong irinh" ft.=v |t,=v [Li Av=6[ir (vi +11-6^0 I/.V>0) Voi u == y =2 la co: Voi I (iigliic;m kep) =-,^(A-+I)' =0