⎪
7
10
13
40
8
5
⇒
1
1
7
10
1
1
13
40
1
1
8
5
y
x
z
y
z
x
+ =
+ =
+ =
⎧
⎨
⎪
⎪
⎪
⎩
⎪
⎪
⎪
quyidagicha belgilashlar kiritamiz:
1
x
a
=
,
1
y
b
= ,
1
z
c
=
.
b
a
c
b
c
a
+ =
+ =
+ =
⎧
⎨
⎪
⎪
⎪
⎩
⎪
⎪
⎪
7
10
13
40
8
5
bu sistemani yechsak, a=79/80. Bundan x=80/79.
To’g’ri javob: A
78(2003-9.48). f( x)= x-1- ctg
2
x funksiyaning boshlang’ich funksiyasini
toping.
A)
x
2
2
- ctgx+C B)
x
2
2
+ ctgx+C C)
x
2
2
- tgx+C D)
x
2
2
+ tgx+C
E) x
2
+ctgx+C
## Funksiya formulasini quyidagicha qayta yozamiz:
f(x)=x-1-ctg
2
x=x-(1+ctg
2
x)=x-
1
2
sin x
. Bu funksiyaning boshlang’ich
funksiyasi: F(x)= x
2
/2+ctgx+C. To’g’ri javob: B.
79(2003-10.13).
x
x
− +
− =
2
1
2
tenglamani yeching.
A)
∅ B) 2 C) 1,2 D) 0,4 E) 0,9
## Bu tenglamani yechishdan oldin uning aniqlanish sohasini topish
maqsadga muvofiq:
x
x
− ≥
− ≥
⎧
⎨
⎩
2
0
1
0
⇒
x
x
≥
≤
⎧
⎨
⎩
2
1
⇒ sistema yechimga ega emas.
Demak, tenglamaning aniqlanish sohasi, shuningdek, yechimlar to’plami
ham bo’sh to’plam -
∅. To’g’ri javob: A.
80(2003-11.9). S
n
arifmetik progressiyaning dastlabki n ta hadining
yig’indisi bo’lsa, S
5
-3S
4
+3S
3
-S
2
ning qiymatini toping.
A) 0 B) -2a
1
C) 2a
1
D) 3a
1
E) -3a
1
## S
5
-3S
4
+3S
3
-S
2
=S
5
-S
4
-2(S
4
-S
3
)+S
3
-S
2
=a
5
-2a
4
+a
3
=
=a
1
+4d-2(a
1
+3d)+a
1
+2d=0.
To’g’ri javob: A.
81(2003-11.15). y=sin(sinx) funksiyaning eng katta qiymatini aniqlang.
A) sin1 B) 1 C) 1/2 D) aricsin1 E)
π/2
## t=sinx deb olsak, -1
≤ t ≤ 1 bo’ladi. Bu oraliqda y=sin(sinx)=sint
funksiya o’suvchi. Shuning uchun y
max
= sin1. To’g’ri javob: A.
82(2003-12.58).
5
5
5
log
log
a
a
a
−
ifodani soddalashtiring.
A) a B) a
2
C) 5a D) 1 E) 0
##
5
5
5
log
log
a
a
a
−
=
a
a
a
a
a
log
log
log
5
1
5
5
⋅
−
= a
a
log 5
- a
a
log 5
=0
To’g’ri javob: E.
83(2003-12.77).
tg
tg
tg
tg
2
2
2
2
2
7
24
24
1
7
24
24
π
π
π
π
−
⎛
⎝⎜
⎞
⎠⎟
−
⋅
⎛
⎝⎜
⎞
⎠⎟
⎛
⎝
⎜
⎞
⎠
⎟
:
ni hisoblang.
A) 1/9 B) 9 C) 1/3 D) 1 E) 3
##
tg
tg
tg
tg
2
2
2
2
2
7
24
24
1
7
24
24
π
π
π
π
−
⎛
⎝⎜
⎞
⎠⎟
−
⋅
⎛
⎝⎜
⎞
⎠⎟
⎛
⎝
⎜
⎞
⎠
⎟
:
=
=
=
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
⎟
⎠
⎞
⎜
⎝
⎛
⋅
+
⎟
⎠
⎞
⎜
⎝
⎛
⋅
−
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
⎟
⎠
⎞
⎜
⎝
⎛
+
⎟
⎠
⎞
⎜
⎝
⎛
−
=
⎟
⎠
⎞
⎜
⎝
⎛
⋅
−
⎟
⎠
⎞
⎜
⎝
⎛
−
2
2
2
2
2
2
2
2
24
24
7
1
24
24
7
1
24
24
7
24
24
7
24
24
7
1
24
24
7
π
π
π
π
π
π
π
π
π
π
π
π
tg
tg
tg
tg
tg
tg
tg
tg
tg
tg
tg
tg
=
tg
tg
tg
tg
tg
tg
tg
tg
7
24
24
1
7
24
24
7
24
24
1
7
24
24
2
π
π
π
π
π
π
π
π
+
−
⋅
−
+
⎛
⎝
⎜
⎜
⎜
⎞
⎠
⎟
⎟
⎟
=
tg
tg
π
π
3
4
2
⎛
⎝⎜
⎞
⎠⎟
=3.
To’g’ri javob: E.
84(2003-7.61). Uchburchakning ikki tomoni 7 va 11 ga teng, uchinchi
tomoniga o’tkazilgan medianasi 6 ga teng. Uchburchakning uchinchi
tomonini toping.
A) 12 B) 8 C) 14 D) 10 E) 13
## Berilgan: ABC uchburchakda AB=7, B D
AC=11, AO=6 (AO-mediana).
BC=? O
Yechilishi: ABDC parallelogrammga to’ldiramiz.
AD
2
+BC
2
=2(AB
2
+AC
2
); A C
(2
⋅6)
2
+BC
2
=2(7
2
+11
2
)
Bundan BC=14. To’g’ri javob: C.
85(2003-9.36). Agar
17
,
7
=
= b
a
r
r
va
35
3
=
− b
a
r
r
bo’lsa,
b
a
r
r +
ning qiymatini toping.
A) 19 B) 20 C) 8
3
D) 9
2
E) 4
6
## (a+b)
2
+(a-b)
2
=2(a
2
+b
2
), (a+b)
2
=2(a
2
+b
2
)-(a-b)
2
=
=2(49+289)-315=676-315=361. a+b=19
To’g’ri javob: A.
86(2003-9.52). To’g’ri burchakli uchburchakka ichki chizilgan aylananing
urinish nuqtasi gipotenuzani 2:3 nisbatda bo’ladi. To’g’ri burchak uchidan
aylana markazigacha bo’lgan masofa
2 2
ga teng.Berilgan
uchburchakning yuzini toping..
A) 12 B) 16 C) 18 D) 20 E) 24
## AF=AD=2x, BE=BD=3x. B
(3x+2)
2
+(2x+2)
2
=(5x)
2
; 3x
2
-5x-2=0
x
1
=2; x
2=
-1/3. D
AC=2
⋅2+2=6; BC=3⋅2+2=8. E
S
ABC=
24. C F A
87(2003-10.48). To’g’ri burchakli uchburchakning katetlaridan biri
ikkinchisidan ikki marta katta.Shu uchburchakning gipotenuzasiga
tushirilgan balandligi 12 ga teng. Uchburchakning yuzini toping.
A) 180 B) 84 C) 120 D) 90 E) 108
## AC=x; BC=2x deb olsak, C
AB
= x
x
x
2
2
2
5
+
=
(
)
A D B
S=
1
2
AC
⋅BC=
1
2
AB
⋅CD. AC⋅BC=AB⋅CD
x
⋅2x=x
5
⋅12;
x=6
5
.
S
∆
=
1
2
AC
⋅BC=
1
2
6
5
⋅12
5
=180. To’g’ri javob: A
88(2003-10.55). To’g’ri burchakli uchburchakning uzunligi 14 va 18 ga
teng katetlariga tushirilgan medianalari uni uchta uchburchakka va
to’rtburchakka ajratadi. To’rtburchakning yuzini toping.
A) 56 B) 64 C) 48 D) 72 E) 42
## Berilgan uchburchakning yuzi S bo’lsin.
S=(18
⋅14):2=126. S
1
Shakldan
S
S
S
S
S
S
1
2
1
2
2
2
2
2
+
=
+
=
⎧
⎨
⎩
/
/
S
2
S
1
=S
2
;
3S
1
=S/2 S
3
S
1
=S/6.
S
shakl
=
42
3
6
2
6
2
2
1
=
=
=
−
=
−
S
S
S
S
S
S
To’g’ri javob: E.
89(2003-10.61). To’rtburchakli piramidaning barcha yon qirralari asos
tekisligi bilan 60
° li burchak hosil qiladi. Uning asosi teng yonli
trapetsiyadan iborat. Trapetsiyaning diagonallari uning o’tkir
burchaklarining bissektrisalaridir. Piramidaning balandligi 4
3
ga teng.
Trapetsiyaning katta asosini toping.
A) 4
3
B) 8 C) 8
3
D) 12 E) 3
6
## Masala shartidan
∠ACD=90° ekani kelib chiqadi.
Piramidaning yon qirralari asos tekisligiga
bir xil og’ishganligi uchun, piramida S
balandligining asosi
∆ACD ning
gipotenuzasi AD ning o’rtasida yotadi.
∆ASE dan AE=SE⋅ctg60°=
B C
= 4 3
1
3
4
⋅
= ; AD=2AE=8.
To’g’ri javob: B
A E D
90(2003-10.63). Ikki vektor yig’indisining uzunligi 20 ga, shu vektorlar
ayirmasining uzunligi 12 ga teng. Shu vektorlarning skalyar ko’paytmasini
toping.
A) 16 B) 48 C) 24 D) 64 E) 32
##
20
=
+ b
a
r
r
;
12
=
− b
a
v
r
larning har birini kvadratga ko’taramiz:
400
2
2
2
=
+
+
b
b
a
a
r
r
r
r
(1)
144
2
2
2
=
+
−
b
b
a
a
r
r
r
r
(2)
(1) dan (2) ni hadlab ayiramiz:
256
4
=
b
a
r
r
;
64
=
b
a
r
r
To’g’ri javob: D.
91(2003-12.31). Parallelogrammning diagonali 8
2
ga teng. Shu
parallelogrammga ichki va tashqi aylanalar chizish mumkin bo’lsa,
parallelogrammning yuzini toping.
A) berilganlar yetarli emas B) 32 C) 64 D) 128 E) 256
## Tashqi chizilgan to’rtburchakning qarama-qarshi tomonlari yig’indisi
teng. Agar u parallelogramm bo’lsa, bu parallelogramm romb bo’ladi.
Ichki chizilgan to’rtburchak qarama-qarshi burchaklari yig’indisi 180
° ga
teng bo’ladi. Agar bu to’rtburchak romb bo’lsa, u holda bu romb kvadrat
bo’ladi. Diagonali 8
2
ga teng bo’lgan kvadratning tomoni 8 ga, yuzi esa
64 ga teng bo’ladi. To’g’ri javob: C.
92(2003-12.41). Parallelepipedning bir uchidan chiquvchi uchta
qirrasining o’rtalari orqali o’tkazilgan tekislik undan hajmi 6 ga teng
piramida kesib ajratadi. Parallelepipedning hajmini toping.
A) 120 B) 144 C) 180 D) 288 E) 276
## Hosil bo’lgan piramidani
uchburchakli prizmaga to’ldiramiz.
Bu prizma hajmi piramida hajmi-
ning 3 baravariga teng.
Asosi piramida asosiga teng va
Balandligi parallelepipedning
Balandligiga teng uchburchakli prizma hajmi piramida hajmining 6
baravariga tengligi shakldan ko’rinib turibdi. Parallelepiped diagonali
orqali o’tgan tekislik uni ikkita uchburchakli prizmaga ajratadi. Ularning
har birining hajmi avvalgi prizma hajmining 2
2
=4 baravariga teng.
Shunday qilib, berilgan parallelepipedning hajmi 2
⋅4⋅6⋅6=288 ga teng.
To’g’ri javob: D.
93(2003-5.43).
cos
cos
cos
x
x
x
=
−
2
1 tenglama [
π; 2π] kesmada nechta
ildizga ega?
A) 1 B) 2 C) 3 D) 4 E)
∅
## cosx ning qiymati [
π; 1,5π) oraliqda manfiy bo’lgani uchun, bu
oraliqda berilgan tenglama -1=cos2x-1 ko’rinishda bo’ladi. Bundan
cos2x=0; x=
π/4+πn/2 (Bulardan 5π/4 berilgan oraliqqa tegishli)
cosx ninq qiymati (1,5π; 2π] oraliqda musbat bo’lgani uchun,
bu oraliqda berilgan tenglama 1=cos2x-1 ko’rinishda bo’ladi. Bundan
cos2x=2. bu tenglama yechimga ega emas. To’g’ri javob: A.
94(2003-9.44). A(1;4) nuqtadan y=-2-2/x funksiya grafigiga ikkita
urinma o’tkazilgan. Urinish nuqtalari abssissalarining yg’indisini toping.
A) –1 B) 1 C) 1/3 D) 2/3 E) –2/3
## A(1;4) nuqtadan o’tadigan to’g’ri chiziq tenglamasi y=kx+b ko`rinishda
bo’lsin. Bunga A nuqtaning koordinatalarini qo’yib, topamiz: 4=k
⋅1+b;
b=4-k. bu to’g’ri chiziq urinma bo’lgani uchun k=y
′ bo’lishi kerak.
y
′=2/x
2
.
b va y ning ifodalarini to’g’ri chiziq tenglamasiga qo’yamiz:
y
x
x
x
x
x
=
⋅ + −
= −
+ +
2
4
2
2
2
4
2
2
2
.
Bu chiziq bilan berilgan funksiya grafigining umumiy nuqtalarini topamiz:
y
x
y
x
x
= − −
= −
+ +
⎧
⎨
⎪⎪
⎩
⎪
⎪
2
2
2
2
4
2
bundan
−
+ + = − −
2
2
4
2
2
2
x
x
x
. Bu tenglamani
yechib, x
1
=-1 va x
2
=1/3 ga ega bo’lamiz. x
1
+x
2
=-2/3.
To’g’ri javob: E.
95(2003-11.20) y=3-
⎪x-3⎪ funksiya grafigi va OX o’qi bilan
chegaralangan shaklning yuzini toping.
A) 9 B) 8 C) 12 D) 6 E) 10
## Modulning ta’rifidan foydalanib, bu funksiyani quyidagicha yozish
mumkin: y=
⎩
⎨
⎧
≥
+
−
≤
3
;
6
3
;
x
x
x
x
shunga ko’ra, grafikni x
≤3 va x≥3 oraliqlarda chizamiz.
3
S=
1
2
6 3
9
⋅ ⋅ =
3 6
To’g’ri javob: A.
96(2003-1.40). To’g’ri burchakli ACB uchburchakning katetlari 8 ga va 10
ga teng. Shu uchburchakning C –to’g’ri burchagi uchidan CE-mediana va
CD-bissektrisa o’tkazilgan. CDE uchburchakning yuzini toping.
A) 2
2
9
B) 2
2
7
C) 2
3
8
D) 3
2
5
E) 3
2
3
C
## S
ACE
=S
∆
/2=(8
⋅10/2)/2=20
AB= 8
10
2
2
+
=2 41 A D E B
h
c
=80/2 41 =40/ 41
Bissektrisa xossasidan AD:DB=AC:BC
AD:BD=8:10=4:5
AD=4x; BD=5x; 4x+5x=2 41 ; x=2 41 /9; AD=8 41 /9;
S
ACD
=(8 41 /9)(40/ 41 )/2=160/9.
S
DCE
=S
ADE
-S
ACD
=20-160/9=20/9= 2
2
9
. To’g’ri javob: A.
97(2003-7.83). Kubning ostki asosidagi tomonlarining o’rtalarini ketma-
ket tutashtirildi. Hosil bo’lgan to’rtburchakning uchlari kub ustki asosining
markazi bilan tutashtirildi.
Agar kubning qirrasi a ga teng
bo’lsa, hosil bo’lgan piramida-
ning to’la sirtini toping.
A) 2a
2
/3 B) 3a
2
C) 1,5a
2
D) 2a
2
E)
2
3
3
2
a
## Hosil bo’lgan piramidaning asosi kvadrat
bo’lib, uning diagonali kub qirrasiga teng.
Shuning uchun piramida asosining yuzi S
asos
=a
2
/2.
Asos tomoni b=a/
2
. Piramidaning apofemasi h
a
= a
a
a
2
2
8
3
2 2
+
=
/
;
S
yon
=4
⋅
1
2
2
3
2 2
3
2
2
⋅
⋅
=
a
a
a
S
t
=
a
a
a
2
2
2
2
3
2
2
+
=
. To’g’ri javob: D.
98(2003-9.7). Ikkita ishchi birgalikda ishlab, ma’lum ishni 12 kunda
tamomlaydi. Agar ishchilarning bittasi shu ishning yarmini bajargandan
keyin, ikkinchi ishchi qolgan yarmini bajarsa, shu ishni 25 kunda
tamomlashlari mumkin. Ishchilardan biri boshqasiga qaraganda necha
marta tez ishlaydi?
A) 1,2 B) 1,5 C) 1,6 D) 1,8 E) 2
## 1-ishchi yolg’iz o’zi butun ishni x kunda, 2-si esa y kunda tamomlaydi.
1
1
1
12
0 5
0 5
25
x
y
x
y
+ =
+
=
⎧
⎨
⎪
⎩⎪ ,
,
bu sistemani yechsak, x=20; y=30
30/20=1,5 marta tezroq ishlaydi. To’g’ri javob: B.
99(2003-11.4).
x
x
x
x
x
x
x
−
+
−
+
−
+ + =
1
2
3
1
4
...
tenglamaning ildizi 10
dan nechta kam?
A) 1 B) 2 C) 3 D) 4 E) 5
Kasrlarning surati birinchi hadi x-1 ga, ayirmasi -1 ga teng bo’lgan
arifmetik progressiya tashkil etadi.
S=
(
)
(
)
(
)
x
x
x x
− +
⋅
− =
−
1
1
2
1
1
2
bo’lgani uchun, berilgan tenglamani
x x
x
(
)
−
=
1
2
4
ko’rinishda yozish mumkin.
Bu tenglamani yechib, x=9 ga ega bo’lamiz. U 10 dan 1 ta kam.
To’g’ri javob: A.
100(2003-9.17).
2 7
7
1
7
7
1
7
7
1
2
⋅
−
≥
−
−
+
x
x
x
x
x
x
tengsizlikni yeching.
A) (0;
∞) B) (-∞;0) C) (-∞;0] D) (-1; 1) E) (1; ∞)
##
2 7
7
1
7
7
1
7
7
1
0
2
⋅
−
−
−
+
+
≥
x
x
x
x
x
x
2 7
7 7
1
7 7
1
7
1
0
2
⋅
−
+ +
−
−
≥
x
x
x
x
x
x
(
)
(
)
1
7
1
0
2
x
−
≥
7
1
2
x
− >0
1
7
2
>
x
2x>0
x>0
To’g’ri javob: A.
Do'stlaringiz bilan baham: |