MDIJl]GB0CRUH0I BfllTnPPHHnH0[1TR0nGDn!/HpCII10nT0fln CHO HOC SINH TRUNG HOC PHO THONG PHAM THI M O N G T I / O N G NGUY§N THUY PHUONG T R A M " Trong qua trinh day hge, mdi hge sinh (HS) cd mgt nang[.]
Trang 1MDIJl]GB0CRUH0I.BfllTnPPHHnH0[1TR0nGDn!/HpCII10nT0fln
CHO HOC SINH TRUNG HOC PHO THONG
P H A M THI M O N G T I / O N G - - NGUY§N THUY P H U O N G T R A M "
Trong qua trinh day hge, mdi hge sinh (HS) cd
mgt nang tuc liep nhan thdng tin va xuli van de
khac nhau,Thuc tidn day hge dcac trudng trung
hge phd thdng (THPT) hign nay cho thay, da sdcac
gid day van duge lien hanh ddng logt, ap dyng nhu
nhau cho mgi ddi luong HS, Giao vien (GV) eung cap
kien thii'c, HS giai cac bai lap (BT) loan Iheo trinh lud
saeh giao khoa (SGK), thieu suphan hda Do dd, viee
ddng ea hgc tap eho mgi ddi tugng HS, phat huy tdi da
nang luc ea nhan, tinh tich cyc, chu ddng, sang lao
hdi (CH), BT phan hda trong day hoe mdn Toan a
THPT
1 Cau hoi, bai tap phan hda trong day hgc
toan d THPT
Helhd'ng CH, BT phan hda phaidam bao dugc su
phat then loan dien cae matve kien thirc, kTnang, thai
ddcua HS.Dodd, cae chuan kien thuc, kTnang quy
dmh trong chuang trinh deu cd trong bgCH, BT phan
hda tren co sd dam bao tinh khoa hgc, chinh xac,
phat huy tlnh tich cyc, sang lao, cd linh he thd'ng va
gan lien vdi thue tidn
Bg C H, BT phan hda thudng duoc phan theo ehu
de, ednhieu CH, dukien tinh hudng vacd suphan
bac de phii hgp vdi timg ddi tugng HS Trong dd, can
du vd so luang BT cung nhu npidung kien thtic cho
timg nhdm HS phan hda Bd CH, BT phan hda dugc
sip xep lang dan theo mifc do nhan thuc, chifa nhieu
yeu iddan dat denang dan kha nang kham pha van
dd, ren luyen cac kT nang hgc lap cho HS (dae biel ddi
vdi HS yeu, kem},
Mdi CH, BT phan hda can hudng de'n vigc Ihue
hien cae mye dich day hgc, khi dat d mdt tinh hudng
cy the deu chua dyng mgl each tudng minh hay tilm
an nhung dyng y su phgm khae nhau NghTa la phai
dam bao ehiic nang day hgc, chu'c nang giao due,
chirc nang phatlrien, chu'c nang kiem tra; tuy nhien,
manh chuc nang nay hay chuc nang khae phy Ihudc
46 Tap chi G i a o due so 314
vao viec khai thac bg CH, BT phan hda va nSng kfc su
pham cua GV nh^m siidung cdhigu quachotilng 6St
tugng HS, Do do, dd'i vdl* he thdng CH, B"Pphan hda
cang "min" se cang phu hop vdi vigc sis dyng cho
trong day hgc
Vidu 7; Tim m dedd thi ham so: y = x= - 2x^ +
(1 -m)x -I- m c3t Injc Ox tai 3 die'm phan biet cd hoanh
dg X , Xj, Xj thda man dieu kien x,' + x^' + X3^<4 (dllhi
luyen sinh dai hgc nam 2010, khdi A)
fie chuyen tai BT nay de'n nhieu ddi tugng HS.ta cdthe phan hda BT tren thanh cac CH nho hon (bai3 chua bai 2; bai 2 chira bai 1; trong dd, bai 1 HS cdthe
de dang giai dugc) nhu sau:
Ba//.'Tim m deddthihamsd:y = (x-l)(x^-x-m) cat tnjc Ox tai 3 die'm phan bigt
Bai2:Tm m dedd thi ham sd:y = x^-2x= + (1-m)
X -I- m est laic Ox lai 3 die'm phan bigt
Bai3:Tm mdeddthihamsd':y=x'-2x'+{1-m}
x -I- m eat loic hoanh tgi 3 diem phan biel cd hoanh do x,,Xj,X3 Ihda man dieu kign:X|^ + Xj^-fX3^<4
He thd'ng CH, BT phan hda phai duge sip xep
theo mdt trinh tu logic, tang dan Vneo thang do mite
do nhan thire cua Bloom (nhan thdc, thong hieu, van dung, phan tich, danh gia, sang lao), dam bao tinh phd thdng dai Ira vaphan hda HS.Dac bigt, hgtho'ng CH,BT phan hda phai thugn lien trong viec them bdt
CH va cd nhifng dulden tinh hudng si}dung phuhoji vdi kha nang nhan thdc eua ti>ng ddi tugng HS;m5i loai CH cd y nghTa va vi tri nhat djnh
W'riu2.-dehuong trinh loan ldp 11, khi day hoc
ngi dung Viet phuang trinh tidp tuyen eua dudng cong phang", td phan d^n cua CH "Cho do thi ham sd:
y=-x*-x=' + 6fCJ';GVcdthexaydungcacCHpl^ag,
hoa: (xem bang 1) .*^:^
Cac CH va BT phan hda dugc neu d u d i f l j i i t e hinh thirc khae nhau, tranh lap dl lap lai gay sunhar^v
* Tnitlng THPT Nguyen Hu^, Binh Tliuan
" Tnriiag THPT flifc Trpng, Um Song
Trang 2HSi
I£in
tdnh
'm
m
BT,CH •
- v i i l phutmg
H n h t i ^ t u y ^ n c i J a
(C) t^i iHem
M(0.e)
- m i l pliuang
Mnh tiip tuyin cGa
(C) Qi giao diim
cOa {C) va (P)
- Viil phifuno trinh
bitl rJng dip tuyin
c6 h3 s i oDc D^ng
-6
- Viit phmmg tiinn
vh H v i n cua IC)
u i t ring tiip tuyin
vudng gfic vdi
duOng mang |d');
< - 6 y - 6 = D
Phln Hell, dll kiin
Onh hu6ng
- Tit Qi HS Oki ofi thS
l i m duOc
- GV cd Ih^ phJI v i n
cac CH llnh baiao iM
kich mich tu d u / cila
HS,
- HS phai 6m 103 HO
giao d i i m eda (C) ii
(?} r i l mdi iam nhu
c i u a )
- HS glJl phuong tnnh
loa dO Iiip Mm
• GV c i i n j Cli lai kiin
thiJc vfi hf sfl gOc ciia
d 1:^10)
- Dl/ doan ciia HS
thUdng sal lira khi col
h e s 6 g i l c c i J a ( d | i a i
- GV giup HS lt)jy
(d'} la 1 »a he sfl gOc
BT.CH End tiuing
- Viit phimno trinti nip tuyin cOa (C) tgi dtjm
c 6 h D i n h d d l ] i F i g - 1 ,
- Viit phuong binli Hip tuyin ciia (C) igl giao H^m cfla (C| va tnjc tung
- Viit phKOng trinh eip
tuydn cua (C) \i\ a(m cdtungdOtiang h
Wit phiTOng Mnh Hip tuyin cua (C| tai giao
• Thay a S CH ggi y d i
binh len kha gifii Viil
phMig Irinti Hip lu/i/i cia (C), biit ring lilp
(uyin song song vdi
Mrtg tning: )< = -£*
+ 2013
• GV cd M ctiuJn b|
thim met s i BT r i n g cao cho HS kha gidi
Chan va giup HS tieh cue kham pha kien thue mdi,
nhin nhan md'i lien he giua cai eu va eai mdi
Vidu 3: Vdi BT Tim gia tri cua m dedo thi ham
sd:y=^^^^iC)diquadiemA(0,*^)".GMc6\hethay
dffl hinh thiic cua BT bang mgl hinh thiic khac nhu:
Tim gia tn eua m dedo thi ham sd: y = ^ ^ ( 0 cat
five tung tai diem co tung dp bing 1/2"
2 Ouy trinh xay dixng bg CH, BT phan hda
' Theo chung tdi, quy trinh xay dung bd CH, BT
phan hda can dugc tien hanh nhusau:
-Bu^ 1: Phan ^ch ndi dung day hpc Ndidung
day hgc phai dya tren ngi dung chuong trinh mdn
hgc, lay SG K lam co sd; ddng thdi, GV can phan tich
rradung theo chuan kien Ihiic kT nang, xac dinh don
yi kien thiic dua vao bai hgc dexaydynghglhdngCH
vaBT phan hoa
•Bude 2: Xac dinh mijc tieu bai hpe.liica SCI n^i
,dung, chuong trinh SGK, GV sexac djnh mue ti&u,
yeu cau cua bai hge ve ehuan kien thtic, kTnang, ttiai
do cua HS GV can xem xet nhieu khia eanh khac
HS cdcai nhin tong quan ve he thdng kien thdc
- Budc 3: Xac dinh noi dung kien thij'c kinang co the ehuyen hoa thanh CH va BT Tu'viec xac djnh
muc dich yeu eau cua bai hge, GV ed the phan ehia nhd ndi dung thanh lung don vj kien thiie, xac djnh ndi dung ed the dal CH hoae xay dung thanh cae BT
• Budc 4: Dien dat cac npi dung kien thdc thanh
CW fa STTuong ling vdi lung ddi tuong HS,GV dua
ra cae CH, BT cy the GV cd the'tuy vao yeu cau eua liJTig dan vi kien thiie, ldng ddi tugng HS detdrndt ngi dung hoac mdt BT lao ra nhieu CH khac nhau
- Budc 5: Sap xep cac CHvaBT thanh he thdng
Obude nay, ddi hdi GV phai bien soan mgt each cdng phu va khoa hgc, !am cho he thd'ng CH trdthanh mdt qua Irinh dan dat HS suy luan kien thiic,
- Budc 6: Dukien tinh hudng strdung va CH, BT phan hda tuong ung Day la khau sau cung, quyet
djnh den su thanh cdng cua hethdng BT, GV can cd cai nhin long quan ve he thdng BT va cae ddi lugng
HS Dua vao budc nay, G V ed the phat hien va dieu ehinh bude 4^, budc 5 cho phu hop hon
Wdu 4 dchuong trinh toan Jdp 12, sau khi day xong bai "Sufucnpg/aoCiJa/)a/rfd'fft/",GVedthexay dyng bd CH, BT phan hda nhSm ren luyen eho HS kT nang bien luan sdnghiem eua mgt phuong trinh bang ddthjqua cac budc sau:
Budc 1 Phan tich noi dung day hoc: Da^ \a ndi
dung quan trgng khi xet do thj cua mgl ham sd, nded sullen kel vdi nhidu ndi dung khae NSm vung kTnang nay giiip HS hieu rd han ban chat eua sutuong giao
Budc 2 Xac dinh muc tieu bai hoc:- Vekien thdc:
HS nam dugc su tuong giao cua hai do Ihj; - Veki
na^ff-'HS bien luansdnghiem eua mgt phuong trinh bing do thj; ren luyen tuduy logic, sang tao, kha nang lien ketva phat hien van de mdi;- Vei'/ia'/d'aHStich cue chu dgng, cd tinh than hop tac trong hgc tap
Budc 3 Xac dinh npi dung kien thuc, kinang cd the chuyen hoa thanh CH va fir(ch5ng hgn nhu kT
nang lam viec tren dd thj, bien ddi dai sd de lam xuat hien do thj da biet)
Budc4,5,6{xembang2\
GVkhidiing ldp, tuy vao trinh ddHSva thdi lugng thdi gian cd the linh hoat si} dyng bg CH, BT phan hda Vdi tiet li thuyet, GV se khdng cd du thdi gian de ren day du cae kTnang hoc tap cho HS;khidd,GV ehl nen cho HS giai den cau b) va dat cac CH b,) bj),c), e,) Cj), d), d,) eho HS kha gidi kham pha
Tap chi Giao due so 314 | 42
Trang 3HS
V6u,
Tnjng
binh
Kha
Gioi
BT.CH
a) Khas sat va ve ad Ih| ham
sfi:
y = x'+3x^~\ (C)
bj Bl^n Iu3n theo m sA nghidm
cJa phJOng trinh
c) Tim cac gid In cua m OS
phi/Ong trinh sau cd 3 rghiim
phin blOl:
2x'-i-6x'+2-m = 0i*)
d) Tim cac gia Ir in de phi/dng
x'+3x'+5-m = OC)
Phan tich, dl/kiin tinh hu6ng
•TilcSHSdSuctithSiafTiflLftJc
- Ddi vdi ham s6 bSc 3, c6 t\\S phan tich
Ihanh tich bic 1 va bac 2 fnKiMg kMng
phai liJc nao cung d i dang iam auQc)
- Bian ddi
{ ' j o j c ' - i - S x ^ - 1 = m
• S i nghiem cOa ptn/Dng trinh chinh la
sA giao ill^m cita 2 Sb 1h|;
U = y - H 3 t ' - l ( C ) 0,^
! > ' = /« i.d)10y vao dA lh| cA kk luan (3 Iti/dng hdP),
- Bian d6i:
Cl » X ^ 4 3 J - ' - ] = - ~ 2
2
- Khflng can nfiu tSl ca c Jc Inrflng hijp nhi/ bi6n luan ma ch? nau tri/Ong hijp PT c6 3 nghidm phan biet
- Lam iLftJngtu nhi/trgn (chuy nhQng gia tri x>1)
BT CH anf! hu6na
- GV cd thS chuJn b| bO CH cho ham bfc 4
- Ngay sau CH nay, GV c6 thg Ihay dSi gia thiit
cila phiMng Irinh {*) va yfiu ciu HS bian dfii <S6 Bm
di/dfig thing (d)
A , ) : x * • ^ 3 ^ ' - 4 + m = 0 (<=>x'-H3jr'-I = -m-»-3)
l>j) :-x' -ix^ +i + 2m = Q
( c = j t ' + 3 j r ' - l = 2m + 2) •
- GV can giup HS phat hl^n 6\H)c Mu bl£n a6i phUdng trirh 66 vk Vii nuii til$n (C) ia rjt quan
hTjro
C^) Tim cac gia trj cua m d£ phiUfig Irinh sau c6
2nshiem: !L + x^+2-m = 0
3
C j ) Tim cac gia Ir; cua m sS phi/dng trinh sau cd
1 nghl?m - x ' ~ix^ +2 + m = 0
f / , ) Tim cac gia Iri cua m de phutfng trinh sau
cd diJng 2 nghiem Are ( - 1 , 1 ) :
x'+3x^'3 + m = 0
3 Phan hda trong day hgc la con dudng nang
cao hieu qua giao dye Viec xay dung va sudyng cd
hieu qua bd CH va BT phan hda se gdp phan tac
ddng tn/c tiep den lung HS De xay dung va sudung
hieu qua bd CH va BT phan hda, ddi hdi GV phai la
ngudi yeu nghe, tan tam voi cdng viec vi thdi gian dau
luldn.Tudac diem, yeu cau su pham va quy trinh
xay dung bgCH, BT phan hda bd mdn Toan, GV can
van dyng mdt each linh hoat nham gdp phan nang
eao hieu qua day hgc loan d phdthdng ndi chung va
oTHPT ndi rieng
SUMMARY
In the study, each student has a capacity to rer ceive and handle the issue differently Thus the need all students in one classroom In this article we wlB tions assignments differentiation In teachingmath
to high school students -^
Tai liCu Iham khao
1 Nguyfin Bi Kim Phmmg phap day hoc mOn Todn
NXB DaihQcauplnun H 2004
2 Phan Trgng Ngy Day hcjc va phinrag phap dgy
hoc trong nh^ truiVng NXB D^i h(ic sit phgm H 2005
3 Dio Tam - Trfln Trung T6' chiic hoat d^ng nh^n
thih: trong day h9c mOn Todn * truwng trung hoc
pha' thflng NXB Dqi hpc supham, H 2010
4 Nguyin Thfi' Th^ch Huwng d&a thuc hi^n chuSn
H 2009
THONG BAO
Tap chi Giao due ra 1 thang 2 \d, d|t mua
thuan tign tai cac bifu cyc dia phUdng (Ma so C192) hoac dat mua true tiep tai Tea soan (so luong Idn) tlieo dja chl: TAP CHI GIAO DyC,
4 "Mnh Hodi Diic, quan Bong Da, Ha N6i.^
Kinh mdi b^n dgc cac ddn vj gi^o ^Cj trudng hoc tiep tuc dSt mua Tsip chi Giao d^^
ndm 2013 Mol lien hg xin giJi ve dja chi tr|n Fax: 04.37345363 , ".,'J Xin Iran trgng cam On
TAP CHf GIAO DgC^ %\
481 Tap chi Giao due so 3 1 4