JOURNAL OF SCIENCF, OF HNUF EducationalSci 2016 Vol 61 No 6, pp 60 68 This paper is available online at hltp,//sldb hnue,edu vn DOI, 10,ISI7V2,154 l(nS 2016 0 1 TIEM NANG VA lltJ DIEM CUA PHAN MEM HIN[.]
JOURNAL OF SCIENCF, OF HNUF EducationalSci 2016 Vol 61.No 6, pp 60-68 This paper is available online at hltp,//sldb.hnue,edu.vn DOI, 10,ISI7V2,154-l(nS 2016-0 TIEM NANG VA lltJ DIEM CUA PHAN MEM HINH H O C DONG CABRI GEOMETRY TRONG DAY HOC TOAN: TRl/CJNG HOP DAY HOC KHAI NIEM HAM SO Nguyen Tbj Nga Khoa Todn - Tin hgc Trifdng Dai hoc Su pham Thdnh phd Hii Chi Mmh Tom tat Bai bao trinh bay lom lal nhflng ldi ich cfia viec ffng dung Long nghe ihong tin day hoc loan ci irtfdng phd ihong Rac biel, chung tbi se lam ro nliung hem nang va tfu diem cua phin mim hinh hoc dong Cabrf Geomelry Irong day hoc khai mem ham sd, Tiep do, chiing loi se irinh bay linh hudng day hoc khai niem ham so cho ihaj vice khai Ihac phin mem mpl each hdp li co ihe hd Ird lich ctfe cho viec ddi nui; phildng phap day hpc iheo hrfbng lang crfbng linh tich ctfe, chu dgng cua hpc sinh vii dac hiiji gnip hoc sinh hieu dtfdc nghla ciia khai mem Ttikhda: Tiem nang, Cabn Geometry, day hoc hiim so Moi dau Trong nhtfng ndm g i n day, vdn de cap thiel ddt cho ngiinh giao due lii phai ddi mbi toiin dien ve nbi dung chrfbng trinh, phtfbng pbap giang day, , nhdm nang eao ehat Itfdng giiio due, Mpt nhfing djnh htfdng dd'i mdi lii tdng ctfbng ap dung hieu qud cong nghe thong nn (CNTT) vdo giang day nhrf tinh than cua chi thj 29/2001/CT-BGD&DT, 30/07/2001 nhan manh " sfl dung C N T T nhfl la mpt cbng cu hd trb dac ltfc nhit cho ddi mbi phtfdng phap giang day hoc lap b tat ea cdc mbn hgc" Ttfbng ttf nhtf vdy, Tai lieu bdi dtfdng giao vicn - Mbn Todn cua Bo G D & D T (2006) cung yeu cau "Can Irfu y lbi vai trb cua C N T T va \ lee tfng dung no vao qua trinh day hge bg mon, [ ] " [ t ] , Tuy vay, SGK chf cd may tfnh bd tiii drfbc de cap trfdng iiiinh \a e(i htfbng dan sil dung, cd thtfc hanh mpt sd t h u d l Cdn lai, viec sff dung cdc phin mem, cac chtfdng trinh day hpc nhrf the nao la thugc vao ban than, kinh nghiem ctia tffng gido vien Cau hoi can dat la: ap dung C N T T vao day hpc nhtf the nao de cd the hd trb d i e life eho viec ddi mdi phtfdng phap giang day hgc tap? Theo chung tbi, day hgc vbi CNTT, ddc biet Id viee dp dung cdc phan mem day hot, lii can thiet, nhtfng quan trgng can cd nhfing suy nght thtfc srf v l cae edng t u do' vbi mot khai niem can giang day, ehung ta at stf dung nhtfng tiem nang gl ciia cdc cong cu nay'' Tai nhCfng thbi diem nao stf dung ehung? Lgi fch cua viec stf dung viec gidng day eua ehiing la lii gi\' Ddi vdi hoc sinh tht nhtf the ndo? Ngay nhan bai: 12/2/2016, Ngay nhan dang 12/6/2016 Lien he Nguyen Thi Nga e-mail' ngaChilOIGSyahoo com Tiim ndng vd Uu diem cUa phdn mim hinh hetc ddng Cabri Geeimelry tremg dgy hpt lodn Doi vbi phan mem htnh bpc dbng Cabri Geomelry, da cd nhilu nghien ctfu dl cap den viec stf dung phan mem day hgc (Nguyen Chf Thanh (2006), Pham Tbanh Phrfdng (2006), Nguyen Bd Kim va cac cgng srf (2008) ) Tuy nhien, vin de nghien ctfu tiem nang va tfu die'm cua phan mem day hgc Toan noi ehung va day hgc khdi niem ham sd ndi rieng de mang lai nghla cho khdi niem thi chrfa drfdc de cap den Bai bao tap trung lam rb nhfing tiem nang va rfu die'm cua phin mem hinh hoc ddng Cabri Geomelry day bgc khdi niem bam sd Tff dd, chung tdi de xuit nhfing tinh hudng day hgc khai niem theo htfdng tang ctfbng tinh lich cffc, chu dbng cua hgc sinh va dac biet gitfp hoc sinh hieu dffbc nghia efla khai niem 2.1 Noi d u n g nghien cuTu Loi ich cua CNTT day hoc Toan CNTT cb the id mot cong cu htfu hieu de ho trd giao viefi (GV) viec day hgc Wiegel et Bell (1996) da chi rang sfl dung CNTT Ibp hpc phffbng pbap giang day loan khdng chi giup cac GV ttfdng lai phat trien viee hie'u cac khai niem loan hgc dtfdc long vdo dd ma ebn cho phep hg phal trie'n nhflng thai dp tfch cflc ddi vbi ltnh vtfc (Marie-Pier Morin [2]) Stf phat trien manh me cua CNTT va nhieu phan mem dae trtfng eua toan hge cung cap cho GV nhflng phtfdng tien cin thiet de phat trie'n nhflng mat khac cua mgt hoat dgng loan hgc thffc sfl (Jean-Marie Laborde [3], Collete Laborde & Bernard Capponi [4]) That vay, cac cong cu cho phep: - Nhan dtfdc nhanh chong bieu dien cua mgt vin de, mot khai niem de mang lai cho no mdt nghia va tao dieu kien cho hgc sinh (HS) chiem tinh chung - Gan ket cac mat khac (dai sb, hinh hoc, ) cua cung mbt khai niem hay mgt tinh hudng - Kham pha tinh hudng bang each Idm xuat hien nhfing hinh dang khdc irang thai dgng - Phal nhfing phdng doan iff mdt thtfc nghiem tffbng tac nghien cffu mgt van dl chfla dffng nhtfng cau hdi md hay mdt sff phflc tap nao va tien hanh nhflng xac minh diu tien - Chuyen tam vao viec giai quyel cac van dl xuat phal ttf cdc tinh hudng ddi sdng ma viec tfnh loan thflbng dai va phflc tap - Tien hanh nhanh chdng viec kiem tra mgt sd ket qua nhan dtfdc Nhtf vay, fliig dung CNTT mgi each hdp If se mang tai nhfing tac dong tich etfc cho qua trinh day hgc, gbp phan vao viec ddi mdi phffbng phap giang day cua pV, lam cho viec hgc cfla HS trb nen tich ctfe va chfl dgng hbn, 2.2 Phan mem hinh hpc dong la gi? Cd nhieu quan niem khdc ve phin mem htnh hoc dgng (HHD) dtfa tren dac trtfng, tiem nang, muc dich hoac tinh nang ciia nb Theo Wikipedia encyclopedia, "moi trffbng HHD la mgt chtfdng trinh may tfnh, nb cho phep ngtfbi sfl dung tao va sau dd thao tdc tren ddi tfldng hinh hgc dflbc xay dflng" Nhff vay, moi trffbng HHD (hay phan mem HHD) cho phep ngffbi dung xdy dflng cac md htnh htnh hgc diia tren mbt so ddi tfldng ban diu la diem, dffdng thang, dflbng trbn, Khi ngrfbi dung thao tac bang each di chuyen cac ddi tffdng dd, lap tffc md hinh cung thay ddi theo Dieu giflp cho ngtfbi dung cb the dtfa eac phbng doan, cac gia Ihuyll va kie'm chffng chtfng Nguyen Thj Nga Chinh lfnh nang "dong" ciia phan mim eb the' cung cap cho ngtfbi diing nhifng ihong lin phan hoi de ho cd the danh gia ehiln Itfdc cua ho dung hay sai va dieu chinh no Cdc phan mem HHD la nhflng phffdng lien phffc tap (b cac cap db khac tiiy theo ph^n mem) srf phong phu cua cdc ddi itfbng If thuylt cung nhtf nhtfng he thdng bieu dien ma no cd Tilm nang cua cac phan mem HHD mgt mat la kit qua ciia nhffng nguyen tdc hoat dong dua tren nhtfng lfnh chat todn boc, mat khae drfa tren kha nang giai quyei nhflng van de ma no co tac dpng.Ba tfng dung liem nang quan trgng cua phan mem HHD la phdng doan kham pha va triJc quan, Srf thdnh cong phu Ihudc thtf nhit vao viec GV phai xdy dtfng nhflng tinh hudng va hoai dbng mgt each can than, thff hai la nhffng cd hbi danh cho HS nhtf vict phong dodn, thtfc hien cac sat Iam thao luan va giai thfch mdi quan he gitfa cac ddi itfbng, tung tiip nhftng giai thfch loan hgc Hien nay, cd nhilu phin mem HHD dtfdc stf dung day hoc Toan nhtf Cabri Geomelry, Geometer's Sketchpad, Geogebra, Trong khuon khd cua bill bao nay, ehiing loi ehi gibi han lai d viec de cap den phdn mem Cabri Geometry 2.3 Tiem nang cua phan mem hinh hoc dong Cahii G e o m e t r y day hoc ham so Phan mem Cabri Geometry la mbt phan mem HHD drfdc \ lel viio nhflng nam 1980 bdi CNRS (Centre Nalional de Recherche Seienlifique) va Trfldng Dai hoc loseph Fourier, Grenoble Mot so tfnh nang ehfnh ciia phan mem la ve htnh, dae, tfnh loan, lii\ \et (quy li'chi cua eac doi iffdng Nhffng tiem ndng va tfu die'm ciia phin mem na\' irong day hoc loan noi chung va day hpc khdi niem ham sd ndi rieng dtfdc lam ro qua mpl s6 cbng cu sau a Congcu "Keo re" Cabri dtfa tren nhfing kiln ihffc toan hgc de cbo phep tao nlitfng hinh iff eat nguyen ihijy hinh hge Neu cdc htnh khong dtfdc ve theo cac phffdng phap phii hdp cua hinh hgc thi di chuyen mgt dbi ttfdng eb phuc vu cho viec dtfng htnh, cac tfnh chiii vii quan he hinh hot "nhin thay" se khong cbn Chflc nang «Keo re» Cabri cung cap cho HS kha nang quan sal cat tfnh chat htnh hgc, moi quan he gifla cdc doi itfgng, hdp thffc hay loai bo viet dtfng hinh Day lii moi chffc nang quan trgng eua Cabri ma moi trrfdng giay bflt khbng thi; ihtft hien Viee keo re (di chuye'n) cho phep hdp thfle hoae toai bd mbi hinh da \ay dtfng hay mot phdng dodn/tinh thit Cu the: - Dl chuye'n de hdp thfft mgt htnh da xay dtfng: di chuyen Lu ca cac diem co the di chuyen drfdc tren hinh de xem hinh cd gitf nhtfng tfnh chit nhtf tinb trang ban dau hay khbng Neu cac tfnh chit gifl nguyen tht hinh ve la hdp thtfc Neu ngtfdt lai, hinh ve khbng hdp thflc vi no da khdng dtfdc ve theo cde tfnh chat htnh hgc dtfdc yeu ciu - Di ehuyen de loai bd mot hinh da xay drfng: di chuyen cat diem cd sd tua \iee drfng hinh de tim mpt vi tri cho phep loai bd htnh ve - Di^ehuyen de hdp thflc mgt phdng doan/tfnh chat: di chuyen tac diem ed sd tua xay drfng hmh de kiem tra tfnh hdp thffc cfla mgt phdng doan hay mot tfnh chal dtfde ihtfe hien bdi hot sinh bang vi?c quan sat tfnh bit bien cua htnh Mol phdng doiin/tfnh chai se bi loai bd la cd the tim thay mpt vj trf ma nb khong ebn thfft Ihi b nfla Tuy nhien, neu thiing ta khbng tim thay phan vf du thi phbng doan/tfnh chit dd cin dtfdc chffng minh ^ ^Nhtf vdy, thong qua viet thao tac trrft tilp tren hinb nhb chtfe nang "Keo re", Cabn cung cap thbng tin phan hoi cho hge sinh de ho danh gia viec dtfng hinh tua ho;'Neu hinh ve khbng giir nguyen cac tinh chit di chuye'n tht can phai tim mdt cliien Irfdc khae de dtfng hinh Chtfc nang f Tiim ndng vd Uu die'm cua phdn mim hinh he)c diing Cubn Geeimelry day hgc lodn "Keo re" eung cap cho bgc sinh kha nang tdc dbng len htnh ve va lam tien trien cac chien Itfbc giai.Thdl vdy, viec di chuyen khbng chl cho phep loai bd eae chiln Itfbt sai md cbn lam tien trien cac chien Itfbc Doi vbi viec day hgc khai niem ham sd chffc nang Keo re cd cdc tiem nang varfudie'm sau: - Sfl dung edng cu "Keo re" eho phep Idm ro mdi lien be giffa hai chuye'n ddng: chuyen dgng cua phan cb sb va ehuyen dgng ciia cac thiinh phan dtfde xay dtfng iff cdc phan cd sd, dieu cho phep dtfa vao y ttfdng ve mdi quan he phu thugc ham - Sff dung cbflc ndng "Keo re" eiing cho phep ehi mbt each ngam an sff bien ihien theo thbi gian Dilu niiy cbo phep dinh nghia mdi quan he phu thugc gifia khbng gian va thdi gian bang each xem xet stf bien thien eua vj tri theo thbi gian - Viee di chuyen mgt diem itf cb the gin kit vbi khai niem biln dbc lap, hbn nffa, viec di chuyen mot die'm thugc mot doi tffdng lai cd the giup hoc smh xdy dtfng ngbia ciia khdi niem mien xac djnh cua ham Ttfdng ttf, mgt ddi tffdng bj di chuyen mgt ddi ttfdng khdc di chuyen tao thuan Idi cho viec di den khai niem bien phu thugc b Cong cu "Tao vet" Khi stf dung cong eu "Tao vei" cho mgt dbi ttfdng, tren man binh se hien thi vet cua ddi tffdng dd nd di chuyen.Trong cac phin mem HHD, ta eb the di chuyen cdc yeu td la khdi dau cua viec dffng hinh Do dd, no cho phep de dang quan sal cdc ddu vet cua diem ma chiing ta tim quy lich Tfl nhtfng phdng doan ma chung ta co the thfle hien tren ban chal cua quy tich, cdc cdu hdi loan hgc se dan den nghi vin ve ddc tinh hinh hgc cua quy tich va tim kiem mgt ehflng minh Khi thtfc hien chflng minh, hgc sinh thrfc hien viec trd lai Ihtfdng xuyen giffa quan sat va linh vrfc loan hoc Cac lap luan cung cd the dan hg den viec tinb chinh eac quan sdt Mgt sd tiem nang cua cbng cu "Tao vlt" day hoe ham sb la: - Sfl dung cdng cu "Tao vlt" cho phep xdy drfng nghta ciia khdi niem bien dgc lap va mien xac djnh viec quan sat drfbc htnh anh htnh hoc cua tap hbp cac vj tri cd the cua bien dgc lap Tffbng tfl, cdng cu "Tao vet" cd the cho phep xay dtfng nghia ciia khai niem bien phu thupc va mien gia trj - Cbng cu "Tao vet" gan lien vbi cdng cu "Keo re", dd viec stf dung nb cung eho phep lilp can stf biln thien tbeo thbi gian va stf phu thudc giffa cdc diem c Cong cu "Chuyen so do" Cdng cu "Chuye'n sd do" Cabri cho phep chuyen mol sb ten mpt dbi ttfdng hinh hpc: - Chuyen so len mbt vecld - Chuyen sd len mot tia - Chuyen sd Ien mgi da giac - Chuyen sd len mbt dtfbng trdn Cd the de cap den mgt sd tiem nang cua cdng cu nhtf sau: - Cho phep HS thtfc hien moi Hen he gifla pham vi sd va pham vi hinh hoc vt cbng cu cho phep xay dffng mbt ddi ttfbng htnh hgc tff mgt so - Khi gin vbi cdng eu "Keo re", nb cho phep hgc sinh nhdn moi lien he phu thudc That vay, viec di chuyen cho phep ihay doi so va keo theo stf thay ddi cua diem dtfdc chuyen so tren ddi tffdng htnh hgc - Cho phep HS thtfc hien mbi lien he giffa pham vi htnh hgc giai tich va pham vi ham qua viec sff dung bieu dien thj cua ham so Thai vdy, nhb vao cdng cu "Chuye'n so do" ta cd the 63 Nguyen Thj Nga ehuyen bien dbc tap Ien true hoanh va bien pbu thugc len true lung 2.4 Khai niem ham so sach giao khoa thong Cdc nghien cflu ve khdi niem ham sd (Rene de Coirel Sophie [5]) phiin biel hai quan mem cd ban sau day + Quan niem dgng cua khdi niem ham sd: dffa tren stfdong bien ihicn ciia hai dai Itfdng Do ta mdi tien he ddng, khdng ddi xtfng gifla hai bien nhdngia tr; ihay ddi hai tap hdp nao va biln phu thudc vao bien Euler da vilt nam ^ nhtf sau "Neu mpt sd dai ltfbng phu thuot vao eac dai ltfdng khac cho neu tiic dai Irfdng khac thay ddi, cac dai Irfdng cung thay ddi theo, liie db chiing la goi eae dai Ufdng lii ham so cua cdc dai Irfdng khac" + Quan niem ttnh cua khai niem bam sd drfa tren srf itfdng flng - ingl ham so hen kei mol sd nhit vbi mot sd cho trrfbc Hankel (1870) dinh nghta ham sd nhtf sau "Ta nbi y la ham sd cua x neu vdi mbi gid Irieua x thugc mbt khoang niio ttfdngflngmpi gia trj xdc djnh eua y ma khbng vt the ma ddi hdi y xac dinh vbi moi khoang bbi cimg mgt quy luat theo x, eung khbng can thiet y dtfdc xac djnh bdi moi bicu thffc loan hoc itfbng minh ctia x, TOI se ggi djnh nghia theo ten Dirichlet vi dmh nghta - djnh nghia dii loai bo tat ca nhiing quan niem cu hdn - la cb ban nhtfng cong trinh nghien ctfu tren chuoi Fourier", Qua phdn tich licb stf htnh ihdnh khai niem ham so va sach giao khoa (SGK), chiing toi nhan thay mac du stf ddng biln thien cua hai dai Itfdng dong mot vai trb quan irong viec hinh khai niem ham sd the nhtfng SGK lai it quan tiim den dac irtfng niiy (Nguyen Thi Nga va Annie Bessot [6]) Trong chrfdng trinh hien thi viet day hoc khai niem hiim sb hoan loan dffa tren quan die'm finh, cbi'nh vt vay ma nd da Iam md di nghia cua khdi niem bien va khai mem ham so Do dd viec quan tam den day hgc khai niem^jiiin sb iheo quan diem dong la thtft srf can Ihiet de HS ndm dtfdc ban chat cua khai niem ham sd Chiing tbi tho rang stf mb htnh hda mot tinh hudng ddng bien thien efla hai dai Itfdng cd the cho phep mang lai nghia cho khdi niem hien va khai niem ham sb "Cac khdi niem bien va khdi niem phu thugc chi mang nghia nhtfng tinh hudng bien thien Cach nhal de nhan thay cai phu thude cai khac la lam eho cbung thay dbi lan IM ttfng cdi mpt de ghi nhan sffbien thien cb hieu qua nao nhtfng thtfng nao ma khong cb srf bien thien, gan nhrf khong the biet ed srf phu thuge hay khong" (Rene de Coirei Sophie [5]) Dac biet nhtf tren da nbi, nhd tfnh chit di ehuyen diem mii phan mem Cabri bo trd rat tot cho viec htnh khai niem ddng bien thien - liln dl cua khai niem ham sd Trong moi trrfbng hinh hgc dong Cabri, stf mb htnh hba cdc dai Itfdng bien thien drfdc thtfc hien bdi vice tao cac diem chuyen ddng Mgt die'm di dgng cd the mb blnh hba cac dai Itfdng bien thien khac (khoang cdch, dien lich, thbi gian) Chung ta cd the dffa vao khai niem die'm dieu khie'n mol die'm khac tien de cua eac khai niem biln dge lap va biln phu thudc Mat khac SGK tai khbng cd mot hoat dbng nao tinh den viec srf dung CNTT irong day hoc khai niem ham sd Trong hien nay, CNTT dang phat incn manh mc va cd nhieu tfng dung quan trpng mpi Unb vtfc eua cube sdng, dd cd nganh giao due Vl vay chiing tdi tiln hanh xay dtfng mbt tinh hudng day hpc eho phep HS tiep can stf ddng bien thien cua hai dai Irfdng nhrf giai doan dau tien cua viec htnh thiinh nen khai mem hiim so Tmh hudng dtfdc tbtfe nghiem tren ddi trfdng HS Ibp 10 nhdm mut lieu gnip HS hicu rb ban chk khai niem ham s6 va nghia cua cac khai niem bien dge lap bien phu thudc Tiem ndng vd tfu diem cua phdn mim hinh hpc dpng Cabri Geeimelry tremg ilgy hpc todn 2.5 Tinh huong day hoc khai niem ham so v6i phan mem Cabri Geometry a Gidi thieu tinh huong Chung tbi da xay dffng tinh hudng day hgc mdi trtfbng Cabri Geometry [7] gdm tinh huong nhd vbi cac muc lieu cu the nhtf sau: •finh huong Tinh hudng Cong viec cua HS Nghien cffu stf ddng bien thien eua hai dai Itfbng hinh hgc (diem) Tinh huong Mb hinh hda mbt tinh hudng thffc te Tinh hudng Mo htnh hba mbt tinh hubng thffc tl Muc tieu Hinh khai niem bien dgc ldp, bien phu thugc, mdi lien he phu thugc gifla hai ddi tffdng htnh hoc, ham hinh hoc Chuye'n tff ham hinh hoe sang ham sd hgc: khai mem bien doe lap, biln phu Ihugc, mdi lien he phu Ihuoc giffa hai ddi iflbng sd Hinh dinh nghia ham sd Sff dung dd thj hdm sd de giai quylt tinh huong thrfc ll Trong khuon khd gibi han cua bai bao, chflng toi chi trinh bay tinh hudng thfl nhat (gdm phieu) Trffdc thtfc nghiem, HS drfdc lam quen vbi cdc cong cu cd ban Cabri Phieu Cdng viic cdn ldm: - Tgo diim A, B, C bdt ki - Chgn Macral, chgn ldn lugt A, B, C ta dugc mdt diim ddt tin Id D - Di chuyen ldn ludt cdc diem vd quan sdt xem diem ndo di chuyen vd diem ndo khong di chuyen didien cdc thong tin vdo bdng sau: Diim ta di chuyen Diem di chuyin Diim khong dl chuyen Mo id dudng dl ciia cdc diim d cgt Ci ddy Macro I dtfdc htnh de HS xac djnh dtfdc I diem (D) cho trtfdc diem khdng thing hang bit kt (A, B, C) Diem D dffdc xay dtfng chi'nh la hinh chilu ctia diem A len drfbng thang di qua hai diem B va C Diem D dtfdc tao thdnh qua Macro cd the di chuyen theo I diem cho trtfbc A, B, C Sau day la each xay drfng Macro I: + Lay diem bat kt A, B, C khbng thing hang + Drfng dffbng thang dl di qua hai diem B va C Dtfng dtfdng thing d2 qua A va vudng gdc vbi dl D la giao diem cua d2 va dl H- Sau do, chgn cbng cu "Ddi ttfdng dau" L J va nbap vdo diem A, B, C + Tiep nic chgn edng cu "Dbi itfdng cudi" + Chgn cbng cu "Djnh nghTa Macro" f Y JA va nhap vao diem D i , dat ten Macrot vd ltfu dtfbi file Macrol NgiiyC-nTlii Nga Phieu Chung ta si kiim thting cdu ira lin cua cm Trin mdn hinh dd ct) sdn diim A B, C vd diem /> lae) ihdnh e/iic Mat ml Chon mdu khdc cho diem A H C, 1) Chon cdng cu «Tgo vii» vd nhdp chuoi len < di diem Di chuyen cdc die'm vd quan sdl Trd ldi lai cdu hdi Hdy md id dudng di cua i de diem d ci'n the > Mf dl chuyin lia cdc diem ii cgt I Philu se guip HS kiem chflng lai cau lia lbi d phieu I bang each ,stf dung cbng cu 'Tao vet" Cabri Chang han, chting loi chon miiu do, xanh dtfdng, vimg, den lan Irfdl cho cac diem D, A B, C tht ket qua d phieu nhrf hinh 1, 2, Vay, mgt diem A, B C di chuyen (bien dde lap) thi diem D di chuyen theo (bi8n phu thudc) Tfl cau trd ldi cua HS GV to the di den the the hda tdc kien thfft Bien doc lap bi^n phu thuoc, stf ddng bien thien tiia hai bien hiim hinh hoc (itfbng flng diem vbi I diem nhSii lEfcltj=y3iJJJiJJ Hinh I.Quy dgo chuyen dong ciia diem D di chuyen diem A Hinh 2.Quy dgo chuyen dgng cua didm D di chuyen diem B # Tiim ndng vd Uu diim ciia phdn mim hinh hpc de'mg Cabn Geometry trtmg day hoc todn |i>,ii-j-i0iw-vi»-iJ5^ :i,'i ^ • • - • - / ) / • • , - ^ J • • - • • ^ ^ ^ • ' "^••J'-.-.y "-'••• "• •: :"'• r - ^ ' • Hinh 3.Quy dgo chuyen ddng cua diem D di chuyen diem C Philu Cdng viic cdn ldm: Hdy xdy difng mgt hdm f gdn mdi diim M ndo dd vdi mgt diim M' rdi liin vdo bfing sau: Bien ddc lap Bien phu thudc Quy trinh xdy difng Muc lieu ciia phieu la HS ltf phat minh mbt ham blnh hgc sau GV dd dinh nghTa khai niem ham.HS cd the xay dtfng ham f cho ttfbng flng mdi die'm M vdi die'm anh cfla nb qua mgt phep bien htnh nao (tinh tien, dot xffng true, doi xflng tdm, ) Chang han, ham f dtfdc xay dtfng qua phep tinh lien nhtf sau: -I- Cho die'm A, B va vecld AB H- Lay diem C khac A va B -I- Chgn cdng cu phep tinh tien, ta dtfdc diem C Id anh ciia C qua phep linh liln theo vectb A^ b Ket qua thiic nghiem Ba tinh huong da xay dtfng dffbc thtfc nghiem trongj budi (90 phut) vbi 34 HS Ibp 10 Quan sat budi thtfc nghiem cho thiy HS thao Iuan rit sbi noi va hao hffng giai quyet cae yeu cau phieu ma GV cung cip Nhff vay, day hgc bing each stf dung CNTT, cu the la phin mem Cabri Geometry, giflp HS nhanh chong nam bit dffbc cac khdi niem va ddng thbi lao htfng thu de HS giai quyel nhflng van de lien quan Tinh "ddng" cua phan mem tao moi trffdng phan hdi de HS ttf danh gia va dieu chinh cae chien ltfdc cua hg Qua thffc nghiem nay, chung tdi da ghi nhan dffbc nhan thtfc cua HS da xuat hiln nhflng y ttfbng xung quanh kbdi niem ham so: + Sff ddng bien thien cua hai dai Iffbng: Neu dai Itfdng thay doi tht dai Itfbng ciing thay doi theo -I- Bien doc ISp, bien phu thugc + Dinh nghTa khai niem ham so -I- Cdc each bieu dien ham sd Nguyen Thi Nga ,j Phan Ibn HS da tiep can dffbc cac van dl tren va thiet lap dffbc 1, ham sd drfa tren srf dong bien thien cua hai dai Itfbng Dong thdi hg cung da van dung drfbc ch$ng nhrf Id mbt cbng eu hiiu hieu de giai quyet cac bai loan thtfc te Ket Iuan Viec khai thac nhflng tiem nang ciia cdc cdng eu Irong phan mem HHD Cabri mot each hOp Ii khong nhiing tao htfng ihu cho HS hgc lap ma tao cd hbi cho ho hoai dbng nhieu hdn ldp hge Tinh nang "ddng" cua phin mem eung cap cho HS thong tin phan hoi de ho co the danh gia chiln ltfdc cua minh dung hay sai va lam liln trie'n cac chien Itfdt Do db, co the han che dtfdc sti can thiep cua GV Ibp hoc, tdng tinh dgc lap cua HS viec xay diing kiln thtfc Ket qua thtfc nghiem mgt sd tinh hudng ma chung tbi dd xdy drfng cho ihay tfnh kha thi va hieu qua cua viec tfng dung phan mim HHD Cabri xdy dtfng cdc tinh hubng da\' hoc khai niem ham sd theo htfbng tich erfc hba hoat ddng eua ngtfdi hgc TAI LIEU THAM KHAO [1] Bg GD & DT, 2006 Tdi liiu boi dudng gido viin - Mdn Todn Nxb Giao due [2] Marie-Pier Morin, 2005 Connaissances mathematiques et didactiqucs dcveloppees a I'aide d'un logiciel de geometrie dynamique quelle intigration possible en enseignemenldes mathematiques? CIEAEM 57, Italy, [3] Jean-Marie Laborde, 1993 Projel Cabri-Geomelre: definition el reaiisalitm d'un sysleme intelligent pour Tapprentissage en geometrie Rapport de recherche Universile Joseph Fourier, Grenoble [4] Collete Laborde Bernard Capponi, 1994 Cabri-Ge'ometre consiiliuinl d'un milieu pour Tapprentissage de la notion de figure geomilrique Tn Recherches en Didatlique des Mathematiques, No 14.2, la Pensee Sauvage, Grenoble [5] Rene de Cotrel Sophie, 1988 Vne etude sur les representations graphit/uc dn memvenienl comme moyen d'acce'der au concept de fonclion ou de variable depcndanic Petit x No 17, 5-27 _ [6] Nguyin Thj Nga, Annie Bessot, 2011 Md hinh hda cdc hien tUdng hiin iliiin irong dgy hqc nhd hinh hgc ddng -Dudn nghiin cifu MIRA Tap cbf Khoa hoc Trubna Dai iioc Stf pham Thanh phd Ho Chf Minh, So 28 (62), tr 55-62 [7] Nguyin Thj Nggc Stfdng, 2013 Day hgc khdi niim hdm so vdi phdn mim Cabri Geometry nghiin ctiu sit ddng biin thiin nhu giai doan ddu liin cua viec xdy dimg khdi idem hdm so Luan van Thac si, Dai hpe Srf pham Thanh phd Ho Chf Mmh ABSTRACT Potential and Advantatages of dynamic geometry software Cabri in teaching and leaming Mathematics: the case of teaching the notion of function This paper presents the benefits of the application of information technology in teaching of mathematics in High school In particular, we will clarify the potential and advantages of dynamic geometry software Cabn Geometry in teaching the concept of function Next, we will present a sitiialion of leaching this concept It shows that ihereasonable exploitation this software can support for innovative teaching methods towards enhancing the positive, the initiative of the students and especially to help students understand the meaning of the contept Keywords: Potential, Cabri Geometry teaching of function ... dpng Cabri Geeimelry tremg ilgy hpc todn 2.5 Tinh huong day hoc khai niem ham so v6i phan mem Cabri Geometry a Gidi thieu tinh huong Chung tbi da xay dffng tinh hudng day hgc mdi trtfbng Cabri Geometry. .. stf dung day hoc Toan nhtf Cabri Geomelry, Geometer''s Sketchpad, Geogebra, Trong khuon khd cua bill bao nay, ehiing loi ehi gibi han lai d viec de cap den phdn mem Cabri Geometry 2.3 Tiem nang cua... chit di ehuyen diem mii phan mem Cabri bo trd rat tot cho viec htnh khai niem ddng bien thien - liln dl cua khai niem ham sd Trong moi trrfbng hinh hgc dong Cabri, stf mb htnh hba cdc dai Itfdng