Cbn hai l6i "chd bAn" cira c6c s6ch d5 6
nhfrng dbng gdn cudi cira cdch 7, nhi6u ban dd
"tinh tudng" ph6t hi6n ra.
BanTrdnTudn Anh,l2{l, THPT Qudc Oai,
Hi Tay cdn luu i Ghi ph6n tich cich 2) : Chi du-o, c vidt
A-c -A-c eB*D.
BDB_D
Xin trao tang phdm cho cdc bii phAn tich tdt
ctra cdcban: NguydnTrudng Khanh, 10 chuy€n
To6n, Qudc hoc Hud, Trdn Dtc'Tradng,22 t6
17, cum 3, phudng D6ng Kh€, NgO Quydn, HAi
Phdng; Vd Thdng Thdi, 8' truong cAp 2-3 NgO
Gia Tu, Cam Ngliia, Cam Ranh, Kh6nh Hda;
PhqmTrong Qu)nh,10A2 khdi PT chuydn To6n
- Tin, DH Vinh, Nguydn Thi Huydn, 11 To6n,
THPT chuy0n Th6i Binh.
Cim on tdtihcdcba;n.
KIHIVI
\?J
LOr GrAr NGAN G9N ?Bii to6n z Ydi a, b, c li, ciic sd duong, hdy Bii to6n z Ydi a, b, c li, ciic sd duong, hdy
tim giri tri nh6 nhdt cira bidu thrlc
' P =( (. sbl[ s./( r*-l')(r.a"l[,*a)5o )
MOt ban de gihi nhu sau :
Ap dung bdt ding thrlc C6-si ta c6
,* *,,r81 a 5a r-> z.E 1 a 5a r-> z.E Y5a ,F (r) t * lrz 5c' ^l! et Y 5r' (3) I 2y .ACLy l= Luu f ring dfng ! THI HOC Nhtn ttng vdcira (1), (2), (3) d6n ddn P > 8.8. \lsb l; 8.6 lso 25 L, Do d6 P nh6 nhat li 8f . 25
Thd nio ? Cdc ban thdy ldi gi6i that ng6n gon chrl ? TuyQt vdi chua ?
rni.N DANG QUAN @dc Ninh)
b 5c
Gidi ddp : AIYH EM SINH odt
Day lh bhi to6n suy luAn l6gic c5 nhidu c6ch
giAi quydt.
Cdch l. GiA sir Tri li ngudi d6 n6i : "T6i lir
Tri", vAy Tri n6i dring n6n cdu tidp theo : "H6m
qua li chir nhAt" cfing dfng. Do d5 h6m nay lh
rhf hai, didu niy mau thuSn vi Tri kh6ng n6i dring vio thf hai. Suy ra ngubi trA ldi : "T6i li
Tri" phAi li Dung vi nghy h6m nay Dfrng n6i
sai. Mdt kh6c ndu vdy thi ngudi n6i : "Ngiy thrl
tu roi luon n5i thAt" phAi ln Tri, nhrmg Tri lai kh6ng n6i that vdo thf tu nOn cAu d6 sai vi ngdy d6 Tri n6i sai. Chi c6 ngiy thrl ba thi ci hai ban
ddu n5i sai. Do d6, Toin bidt du-o. c h6m d6 li
thrl ba, ngudi tri ldi trudc ld Dflng vi ngudi tri ldi sau la Tri.
Cdch 2. Gii sri Dflng n6i cAu : "Ngiy mai li
thr1s6u" th n6i dring thi h6m nay li thf ndm n6n
Dfrng phii n5i sai. MAu thu6n ndy chrlng t6 Tri
phii n6i cAu niy vi cAu : "Ngdy thf tu tOi 1u6n nOl ttrat" l) hai cAu mAu thu6n nhau n6n ngdy
hdm d6 Tri n5i sai. Mdt khdc ngudi n6i "TOi li
Tri" phAi li D[ng n€n ngdy d6 Dfing cflng n6i
sai. Tir d6 suy ra kdt quA nhuc6c! 1.
Qud nhidu ban giAi dring n€n uu ti€n c6c ban
giii hon m6t c6ch sE duo.c tang phAm : Dttong
Dtltc Ki€n, 11A2, THPT YOn Lac 2, Vinh Phric,
Nguy€n Anh Nguyat, td 28, phd Tan Phri,
phuong Tdn DAn, Tp. ViCt Tri, Phri Tho.
Nhitiu ban li lu6n vdi trang bang c6ch ldn luot
xem tdt chcdc ngdy trong tudn. C6 thd nhAn x6t
cAu 1, cAu 2 cing dring cirng sai nhtmg kh6ng thd ctng dring n6n cing sai, tuong tu cAu-3, cAu
4 cing dring, cing sai nhung kh6ng th€ ctng
dring nOn ctrng sai. Tt d6 suy ra kct quA.
Cim on c6c ban vd xin mdi xem x6t hai chidc ddng hd trong bii to6n du6i day.
LTN
HAI CHEC DONG HO
Ddng hd cira Minh v) TuAn ddu chay nhanh.
Ddng hd cira Tudn chay nhanh hon ddng h6 cira
Minh 0,5 phrit m6t nghy. Vio 12 gid trua ngiy
chir nhat, ktri ce 2 ddng h6 de chi dfng, Minh vdn ddng hd cira minh chAm lai 2 phrit, TuAn
vdn ddng hd cria minh chAm lai 3 phdt. Vhi ngdy sau ddng h6 cira Tudn chi dring vio 12 gid
trua, cdn ddng hd cira Minh chi dring vio 12 gid
trua ngiy h6m sau d6.
H6i ddng hd cira m6i ban chay nhanh bao
nhi6u phrit m6t ngdy vi chi dring vio ngiy n)o?
INAN XUAN TIEP
(12A9,THPT Ngb Quydn, Hdi Phbng)
ETrong m\t ki thi hoc sinh gidi ddnh cho ldp 8
cia tinhT.B vla qua c6 bdi todn : "Tim gid tti lon
nhdt vd nhd nhdt cila bidu thtc A = 4x1y ndu
4l+y2=1" vd vdn bdn htdng ddn chdm nhu,out
"+Tac6 :2(4i + y'1-12* -y)2 = (2x+y)2 >0
+ Suy ra : (2x-y)2 32 do 4l + y2 = 1
+ Xit x, y ld cdc s6'hfiu ti thi khdng cd sd hrtu il
ndo binh phuong bdng 8 nAn khdng tim dtoc gid
tri ltn nhdi vd nhd nhdt cia A.
+ Ndu chdp nhdn tdn tai a dd a2 = 2, khi d6
2* -y l6n nhdt bdng lal vd nhd nhdt bdng -lal,
do d6 4x -2y lon nhdt bdng 2lal vd nhd nhdt bdng
-tlal
Tda soan c6 y ki1n th|'ndo ?
HoANG TUAN ANH (Htns Hd -TB)
(- N6i cho chinh x6c thi bii to6n niy hoc
sinh lop 8 kh6ng "xoi" du-o. c ! Bii to6n bio 'tim"
mi d6p 6n lai ddm tr6 lbi li "kh6ng tim duoc"
thi cdn gpi ld ddp dn litm sao du-o. c ? Bang c6c
ki€n thrlc cfra cdp THPI thi mdi chrlng minh
n6i: kh6ng tdn tai gi6 ti lon nhdt vh nh6 nhdt
ctra A ndu x, y lb sd hfru ti. Ldi gi6i khdc mA ban
gui vd cfrng kh6ng dring. Ndu bii to5n ndy dirng
cho hoc sinh lop 9 thi lai qu6 binh thuong.
Mong cdc nhi lim dd thi luu y. Chm on ban.
8 Chung em dto. c biei fi ki thi ndm hoc
2000-2001 sd khbng duoc ding phtong phdp
nghiAm kip dd ldm cdc bdi todn tidp tuy1n vd sa tidp xic cila hai dd thi. Tai sao Ddi TWN phdt
bdng chtong trinh 6n thi cila thdy gido Nguydn
Thxongvd thdi vdn ding dtoc ?
(Hoc sinh trudng THFrI Bach Ding, Quing
Y€n, YOn H*g, Quing Ninh)
sj Cdc ban phii chhp hinh quy dinh cira BO
GD-DT lb khOng duoc ding. Ddi THVN ph6t
lai bang bni giang cria thdy NTV c6c ndm trudc
n6n m6i thd. Mong Del THVN luu j chinh li
c6c bbi gi6ng theo quy dinh m6i.
*fr L,\,.,.- L< n/<.a.-,*i-
35 NAM.KH0I THPT CHMN TON.TIN TBU0NC DAI HOC VIIIH
Vdo th6ng 10 n5m 1966 theo quyet dinh cua
BO Gi6o duc, 15 em nam n[ hoc sinh tir Quing
Binh ddn Nam Hi d5 vucrt qua bao chdng ducrng
gian nan vdt vh do,chien tranh ph6 hoai ctra k6
thn dd tu hOi vd miiin que Yen Da, xI Thach
Binh, huy6n midn nrii Thach Thdnh tinh Thanh H6a du khai gi6ng l.rp 8 - toiin ddu ti6n cua khdi Toiin dac br6t, nay lh khdi THFrf chuy6n Toiin - Tin truirng DH Vinh.
Tt I969 - lgTo',thdy trd cdc l6p To6n dac bi6t
cing vdi khoa To6n chuydn vC ving bien
Qulnh NghTa, Qulnh Minh, Qulnh Di6n huydn
Qulnh Luu vi xd Di6n Trubng huyOn Di0n
ChAu tinh Nghe An.
Ndm 1972 do chien tranh 6c liet, d<j tidp tuc
su nghiCp d)o tao, d6m bAo an toin, kh6ichuy0n Todn duoc 10nh chuydn den Phf Thinh, chuy0n Todn duoc 10nh chuydn den Phf Thinh, HAu Thlnh, huy€n YCn Thdnh vd rir nf,m hoc
19'73-1974khdi chqydn Todn - Tin cirng trulng
dai hoc Vinh trd v6 thdnh phd Vinh.
Tir nAm hoc 1975-1976 ddn nay, khoi THPI
chuy0n Toiin trd thdnh m6t don vi dOc lAp vi
nim i 996 khdi m& th6m he chuy6n Tin.
TrAi qua 35 ndm xAy dung vi phiit tridn kh6i THI']'l'chuyOn To6n - Tin dI dlo tao duoc gan
hai ngdn hoc sinh tdt nghiCp THPf vd hdu het
c/rc em dA ducvc tuydn chon vio c6c trudng DH
co uy tfn o trong v) ngodi nu6c. 'l'heo con s6
thong k€ chua dd-v du nhidu hoc sinh di b6o v€
tirinh c0ng luAn iin I-SKH ; Pham Thd Long, LC
'fuan }loa, Dinh Nho Hho... Hon chuc ngu6i da du<;c nhh nuSc phong tdng GS, PGS nhu' : Phzrrr-r
The [.ong,'frAn Ngoc Giao, Le Mi Til. I-€ COng
Tri3m, Le Tudh lloa... TS TrAn Quyet Thing (hoc sinh chuy6r: todn kh6a 5) hien Ie Ph6 Chi tich UBND tinh i{r\ Tinh" Hhng tram hoc sinh
cua khoi dd bAo ve thhnh c6ng luAn iin TS, ThS,
li giring viOn tror-rg cdc trudng DH, CD, lh girio
vi6n cua cdc trulng ning khieu cr nhidu tinli, ii
chuy6n vi6n gi6i trolrg cric Vien nghier-r c(ru,
Nhi xuAt bAn, cdc BO, ciic Corrg ty, Tiing c6ng
ty tren moi midn cua dat nu'6c.
Cdn 50 thdy c0 giiio cila trudng DII Vinh dE
truong thinh tir khoi chuydn Todn g6p m6t phdn
ISN : 0866-0853 Chdbin tai Tda soan
Chi so z 12884 In tai Nhh mdy in Di6n Hdng, ng6 187 phd Giang V6 ME so : 8BT94M1 In xong vn nop luu chidu tnang iO nam 2001
quan trong vho c6ng tdc dlo tao, nghi0n ciru v)
quAn li cua nhi trudng. Cho ddn nay khdi c6 8 HS doat giAi Qudc te vd khu vuc, gdn 50 HS
doat gi6i Quoc gia, h)ng chuc HS doat giAi brio
THTT. Trong 5 nam gdn dAy. ndn-r nio chng c6
HS doat girli Olympic To6n Chau A -Th6i Binh
Duong, ttt 5 ddn 7 em doat giAi todn Quoc gia. 100Va hoc sinh h€ chuy,On da thi d6u vdo c6c
trudng dai hoc, trong d6 c6 nhidu em d6 thu
khoa, m6i ndm c5 hing chuc em duo'c cu di o
nu6c ngoli hodc duo-c cl.ron vio c6c ldp tli nAng cua c6c lrudng dai hoc lcin 6 tr-ong nu6c.
Khoi 1u6n ghi nh6 cOng lao cua cdc thdy gido day to6n nhidu nam 6 khdi : Nguy€n Thric Hdo,
Nguyen Van Bang. Trin Van Hao. Nguy6n Van
An, Kr€u Huy LuAn. Hoing K!, Truong Dirc
Hinh, Hh Huy HAn. TrAn Dfc Mai, Van Nhu
Cuong, Nguy6n Tuong QuAn, L0 Huy Hring, Le Quang Phan, Nguy6n Thdi Hde, Bii Tulng Tri, Nguydn D)nh NhAn, Trdn Dinh Vi0n. Ilodng Trong Thrii, Nguve n Van DAm, D6 Manh Hirng,
Dlo Tam, N-eur,6n Viet Hii, Nguy6n Quang
Vith. H6 Bfnh. LC Thon-u Nhat...
Hi0n nay' kh6i THPT chuy€n To6n - Tin c5 35
gi6o vi6n, trong d6 co ti gi6o vi6n toiin ( I TS v) 7 ThS). Trudng DH \/inh thuong xuy6n cu ciic
gi6o vi6n c6 nhieLr kinh nghiOm d c6c khoa
Todn. Li'. Cong nghC th6ng tin... r,d day chu1,€rr d.i clto cic hou sinh.
V6i nhung d6ng gdp to lcrn cua lrao lhe hC
thdy trb trong 35 nim qua. don vi dI duoc tan_e
nhi6u Bang khen cua UBND tinh Ngh€ An. Bang khen cua Tdug Li6n doin i-ao dOng Vi6t Nam, Bing khen cua 86 tru&ng 86 Giiio dr-rc r.,i) Ddo tao, Bang khen cua Thu tu6ng Chinh PhLi i,d thinh tich xuat sic trong cdng tdc dio tao.
NCKH, btii dudng hoc sinh gi6i. Dec bi€t thhng
10 nanr 2001 Chu tich nrrdc COng hba Xi h6r
Chri nghTa Vi0t Nanr di ki quydt dinh tan-c Hr,rAn chuong Lao d6ng hang Ba cho khor THPT chuydn Toiin - Tin trudng Dai hoc Vinh.
Gi6:3000dBa nghin ddng Ba nghin ddng