SINH GIOI BAp AN, gtEu DIEM CHAM THI HQC xAwt HQC 2ot2 2W.. Phdng GD&DT Vd Nhai.[r]
Trang 1rrBND truyEN vo NFrAr on TIrr crAo LUU HQC SrNH CrOr LOp s
oE cniyn rntc
Biii 1 Thuc hi6n:
a,Rfitgonbi6uthirc: A:-1-+ 1+ I + + I
b,Chfingminhringv6imoix,ytalu6nc6: x, + y, +12 x.y + x * y
c, Gi6i phuong trinh: *' - 31*1 - 4 : 0
hfc y4:( *'-t - I ') (-o-t-"0)
["0 - x2 +t
", +lJ'("" t+x, )
a, Rrit gon bi6u thric M
b, Tim giS,tribe nhStcria M .
Biti 3 Gidi bdi todn bdng cdch tdp phaong trinh
M6t ph6n sd c6 tu s6 b6 hcvn mdu s6 ld 11 N6u bot tu s6 di 7 don vi vd tdng mfiu
I6n 4 don vf thi sd duoc phAn s6 nghich d6o cria phAn sO da cho Tim phAn sO OOf
Biti 4 Cho tam giSc nhon ABC Ggi D, E, F theo thri tu ld trung di6m cira AB, BC, CA.
Ggi M, N, P, Q theo thri tU ld trung di6m cira AD, AF, EF, ED
a, Tf giSc MNPQ ld hinh gi? Tai sao?
b, Tam gi6c ABC c6 diOu ki6n gi thi MNpe ld hinh cht nhat?
c, Tam gi6c ABC c6 didu ki6n gi thi MNpe ld hinh thoi?
Biii 5 a, Chring minh ring: P = J=* 7"7* ( 1* I * +"'+roff'1
b, Tim giatrinho nh6t cua bieu thtlc: A : 2010x + 2680
x2 + 1
c, Tim x bit5t: 4"- I2.2" * 32: 0
(Gidm thi coi thi kh6ng gidi thfch gi th€m)
vrox roAN s
(Thdi gian ldm bdi 90' kh6ng kA rhdi gian giao di)
Trang 2Biii 1 (6 d), Thgc hiQn ditng:
a.(2divnlTcrc6: A :irl f +
58
n+I
.1
+
-l ^.^
5n+L
L-;
b,(fucti\m)Tac6: *'+Y'+1 ) x'Y+x*Y e *'+y'+1-x.y-x-y > o
o2v3 +2yt+2-ZxY -2x-2Y2 0
e ("'+y'-2xy)+("'+ | -2x)+(y'+ 1 -2y)>0
oi" _yf +(*_1)r+(y _ 1)r > 0 eetdingthirclu.nlu.ndirng.
c, (2iI) PhAn ilch vd gidi itting: x' - 31"1 - 4:0
Gi izphuong trinh ndy dugc nghiQm cua pt lir:
Biii 2 (4 d), mdt i, 2 tt; Ldm ctfing:
=, M-ffi1x4+1-x2;
b, Bi6n ooi : u- 1 - *' Mb6nrratnri
<> x:0
1^
= x2 +I 12+3x -4 o
Phdng GD&DT Vd Nhai BAp AN, gtEu DIEM CHAM THI HQC SINH GIOI
xAwt HQC 2ot2 2W
LI
=;(;
)L
2
X
S_
3l"l :*-+
3x-4: 0ho4c {-a; a\ thoa mdn
xo -l-xo +x'-7
x2 +l
Bdi 3 (2 d),Ggi tu sO .uu phdn ,O cAn tim lir x thi mau sd ctra phAn sO
"An tim ld x+11'
PhAn sO
"an tim lir ;n (x ld s6 nguyOn kh6c -11) Khi bort tu s6 di 7 vd tdng mdu
'O + 1Ccr" vi) ta dugc phdn sO
Theo bdi ra ta c6Phuong trinh #i: ::
Gi6i phucrng trinh vd tim dugc x : -5 (tho6 m6n) Tir d6 tim dugc ph6n t6 -;
3 lon nhAt o xt+l be nhat <+ x2 : 0
x2 +l
# (xkh6c -15)
BdU (5,0A, Vd hinh vd ghi gt, kl dting cho 0'5 d' mdi i l
'5 d'
al Theo gt ta c6:
MN t t DF; MN =lrtl z l+
MN llPQ;
PQt tDF;eA=lor >_) I
1)
3n +5'
MN =Pa VQY MNPQ ld hinh binh hAnh'
Trang 3vQy dc MNPQ ld hinh cht nhat thi tam gi6c ABC ld tam gi6c cdntai A.
c/ Gi6 sri MNPQ le hinh thoi thi: MN: Me
vdy tam gidc ABC vu6ng t4i A thi MNrpe rd hinh thoi
Bdi 5: (se mdi ! I ct:
a, Tim duoc: p : 1*1*-1 I I
I - 7*7*t+ "+"'+rod
:****j* * -1-.I*l*l* * 2.2 3.3 4.4 -" I - 1 l I l, l 1
100 t00 ti- L3- 3At"'* gg.tgg : r - -*t-t* ;-
_ ,199
r =
- < I Vav p<1.
loo loo 7J
b, Tim ducyc: A_
-335x2
2010x +2680
x2+1
bl Gia sri MNPQ la hinh chfr nhAfthi: Mp : Ne
- 335 + 335x2 + 2010x + 3015
Ne = oo =;)
x2+1 = -335 * 335G 13)'z >
-335
x-+l
YQy gid tri nh6 nh6t cta A td _ 335 khi A. J.
c, Tim dugc: 4" _ 12.2" *32 :0 <+
o 2"(2" _ 4) _ B(2" _ 4) _ 0 <>
e (2" - zt)e" -zr) - o €>
e 2*:23 hodc 2^ : 22 <)
2*.2* - 4.2" _g.2* +4.8 - 0
(2" - BX2._ 4) _ 0
2" 13 -0 ho{c 2"-22:0
X =3; x:2
(Hpc sinh ldm cdch khdc dring vdn cho
di€m t6i aoS