D thing hang.
Tim giatri Idn nhat cua bieu thtfc: Q =— Cfiu Ị
X - 1
1) Giai phiTdng trinh = x -1-1 ^..
2) Giai he phiTdng trinh: \ ~ ^ l3x + 2 y - l l l3x + 2 y - l l
Cfiu IỊ Rut gpn bieu thtfc P = 1 1 ^ 2%/a-a 2- V a j a - 2>/a
v d i a> O v a a; t 4
CSu IIỊ (1,0 diem) Mpt tam gidc vuong chu vi la 30 cm, dp d^i hai canh goc
vuong hdn k6m nmhau 7cm. Tinh dp d^i cic canh cua tam gidc vuong d6.
Cfiu IV. (2,0 diem)
Trong mat ph^ng tpa dp Oxy, cho di/dng th^ng (d): y = 2x - m + 1 va parabol (P): y =^x^. parabol (P): y =^x^.
^ly 'unmvrnruvTn-Knanq ViCt
1) Tim m de dtfdng thing (d) di qua diem Ă-l; 3).
2) Tim m dé (d) dt (P) tai hai di^m phan biet c6 tpa dp (x,; y,) (xj; y^) sao
cho XiX2(yi + y2)-H 48 = 0
Cfiu V. (3,0 diém) Cho diTdng tron tam O diTdng kinh AB. Tren dirdng tr6n lay
diim C sao cho AC < BC (C ^ A). C^c tiép tuyén tai B v^ C ciia (O) c^t nhau
5 diem D, AD cit (O) tai E (E A). 1) Chu-ng minh BÊ = AẸDE 1) Chu-ng minh BÊ = AẸDE
2) Qua C ke di/dng th^ng song song vdi BD c^t AB tai H, DO c^t tai F. ChiJng minh tỉ giac CHOP npi tiep. minh tỉ giac CHOP npi tiep.
3) Gpi 1 la giao diem cua AD vk CH. ChiJng minh I Ik trung diem cua CH.
Cfiu VỊ (1,0 diem) Cho hai so diTdng a, b thoa man - + i = 2.
a b
Tim gia tri Idn nhat cua bieu thtfc: Q = — Cfiu Ị Cfiu Ị
á' + b^ + 2ah^ b^ + â + 2bâ ' Uvtdng din giai Uvtdng din giai
1) x - 1 = x + l o x - l = 3(x + l ) o x - l = 3x + 3 o x - 3 x = 3 + lo-2x=4«x = -2 o x - 3 x = 3 + lo-2x=4«x = -2
1) x - 1 = x + l o x - l = 3(x + l ) o x - l = 3x + 3 o x - 3 x = 3 + lo-2x=4«x = -2 o x - 3 x = 3 + lo-2x=4«x = -2
P = 2 7 a - a 2-^/aJ ' a - 2Va 1 1 ^/a+1
^ ^ • >/a+ 1 _ 1 + V a (VI - 2)
V I(2- 7 I ) 2 - VlJ • 7^(7^ _ 2) 71(2-VI)" ^/I + l
= -1
Nhfin x^t: Day cung la hki tokn rát dẹ
Cfiu IIỊ Gpi dp d^i canh gdc vuong nhd la x(cm) (Dieu kien 0 < x < 15)
Dp d^i canh gdc vuong kia 1^ x + 7 (cm)
Dp d^i canh huyen 1^: 30- (x + x -1- 7) = 23 - 2x