VI 1.(0,5 diem) Tinh cac tich v6 hif(Jng AIJ.AD ;A C.B D.
1.Hiiy lap bang Ian só.
2. Hay lap bang Ian so, Ian sual ghep Kip la cac doan \\U do dai la 7, Idp dau lien la [23 ; 30), Ú1p ihỉ hai la |31; 38)... dau lien la [23 ; 30), Ú1p ihỉ hai la |31; 38)...
C a u V. (2,0 diem) Viél phu'ctng Irinh chinh utc cua clip (E) trong moi Iru'cJng hdp
sau:
1. ( E ) CO mot dính 6,(0; - 12) vii c6 mot tieu diem F, (-5; 0). 2. ( E ) di qua hai diem M{3: 2N/3),N(-6; S).
C a u V I . (0,5 diem) Chufng minh trong tam giac ABC, la c6 :
sin(A - C ) - s i n B = -2 cos A sin C.
uiy iwnn wiv uvvn Miaiig viiji D A P A N T H A M K H A O
Cau Dap an Diem
I (3,0 (3,0 die III)
1. (1,0 diem) Giai haft phtf</ng trinh...
Dal u = X - + 3x + l.bál phi/dng trinh trcif lhanh u(u - 4) > 5
<:=> i r - 4 u - 5 > { ) 0,25 <=> u < -1 u > 5 V('Ji u < - 1 , la c6: x~ +3x + 1 < - 1 <=> X " + 3x + 2 < 0 J » - 2 < x < - l . - V('li u > 5, la c6: x" + 3x + 1 > 5 o x" + 3x - 4 > 0 x < - 4 x > l <=>
Vay bat phiTctng Irinh da cho c6 tap nghiem la: S = ( - ( » ; - 4 | u l - 2 ; - l | u l l ; + x ) -
0,25 0,25 0,25
0,25
1. (1,0 diem) G i a i hat phiftfng trinh...
x^ + 2x — 3
BPT da cho di/dc vict iai nhiTsau - I < — — < 1
- x ^ + 3x - 3
0,25
V i - X - + 3x - 3 CO • ^ ^ ^ ^ ncn - x " + 3x - 3 < 0,
A = -3 < 0 V x e : 0,25
Do do BPT da cho lifdng di/tJng
X -+ 2 x - 3 > - x - + 3 x - 3 [ 2 x - - x > 0 x~ + 2x - 3 < X " - 3 x + 3 5 x < 6 0,25 x < 0 hoac x > — 2 . 6 x < - 5 X < 0 1 6- - < x < - 2 5
Vay tap nghiem cua bál phiTcing Irinh da cho la: i 6
S = ( - o o ; 0 ] u
2 5
0,25