## sinx=t deb belgilasak, cost<0 bo’ladi, bundan
π
π
2
3
2
< <
t
yoki
π
π
2
3
2
<
<
sin x
. Bu tengsizlikning esa yechimi yo’q.
To’g’ri javob: E.
53(2002-2.35).
xdx
a
a
≤ +
∫
4
0
tengsizlikni qanoatlantiruvchi a ning
qiymatlari oralig’i uzunligini toping.
A) 6 B) 5 C) 4 D) 8 E) 7
##
xdx
x
a
a
a
=
=
∫
2
0
2
0
2
2
dan
a
a
2
2
4
≤ + ; a
2
-2a-8
≤0; (a+2)(a-4)≤0
[-2;4] oraliqning
uzunligi 6 birlik. -2 4
To’g’ri javob: A.
54(2002-2.51). 2sin6x(cos
4
3x-sin
4
3x)=sinkx tenglik hamma vaqt o’rinli
bo’lsa, k ni toping.
A) 12 B) 24 C) 6 D) 18 E) 4
## 2sin6x(cos
4
3x-sin
4
3x)q 2sin6x(cos
2
3x-sin
2
3x)(cos
2
3x
+
sin
2
3x)=
=2sin6x(cos
2
3x-sin
2
3x)=2sin6xcos6x=sin12x.
sin12x=sinkx dan x=12. to’g’ri javob: A.
55(2002-3.9) Agar a(x-1)
2
+b(x-1)+c=2x
2
-3x
+5 bo’lsa, a
+
b
+
c yig’indi
nechaga teng bo’ladi?
A) 7 B) 8 C) 6 D) 4 E) 5
## a(x-1)
2
+b(x-1)+c=ax
2
-2ax+a+bx-b=ax
2
-(2a-b)x+a-b+c.
Bundan
a
a
b
a
b
c
=
− =
− + =
⎧
⎨
⎪
⎩
⎪
2
2
3
5
Demak , b=1; c=4. a+b+c=7.
To’g’ri javob: A.
56(2002-3.78). cos
2
x+6sinx=4a
2
-2 tenglama a ning qanday qiymatlarida
yechimga ega?
A) [
− 2 2
;
] B) [0;
2
] C) [0;2] D) (-2;2) E) [1;0)
## max(cos2x+6sinx)=6 va min(cos2x+6sinx)=-6 bo’lgani uchun.
4
2
6
4
2
6
2
2
a
a
− ≥ −
− ≤
⎧
⎨
⎩
⇒
4
4
4
8
2
2
a
a
≥ −
≤
⎧
⎨
⎩
⇒
a
a
2
2
1
2
≥ −
≤
⎧
⎨
⎩
⇒ a
2
≤2; a ≤ 2 ;
−
≤ ≤
2
2
a
. To’g’ri javob: A.
57(2002-3.80). (8x-1)(x+2)ctg
πx=0 tenglama [-2;2] kesmada nechta
ildizga ega?
A) 5 B) 4 C) 6 D) 7 E) 3
##
a) 8x-1=0; x
1
=1/8. bu ildiz [-2;2] kesmaga tegishli.
b) x+2=0; x=-2. bu chet ildiz, chunki ctg2
π aniqlanmagan.
c)
ctg
πx=0; πx=π/2+πn; x=1/2+n;
bu ko’rinishdagi sonlardan -3/2; -1/2; 1/2; 3/2 lar [-2;2] kesmaga tegishli.
Shunday qilib, tenglamaning [-2;2] kesmadagi ildizlari 5 ta.
To’g’ri javob: A.
58(2002-4.17). Geometrik progressiyaning mahraji 1/2 ga teng.
b
1
(b
2
)
-1
b
3
(b
4
)
-1
⋅
...
⋅
b
13
(b
14
)
-1
ning qiymatini toping.
A) 64 B) 32 C) 16 D) 128 E) 256
## b
1
(b
2
)
-1
b
3
(b
4
)
-1
⋅
...
⋅
b
13
(b
14
)
-1
=
b
b
b
b
b
b
q
1
2
3
4
13
14
7
1
⋅ ⋅ ⋅
=
⎛
⎝
⎜
⎞
⎠
⎟ =
...
2
7
=128.
To’g’ri javob: D.
59(2002-4.19). Arifmetik progressiya hadlari uchun
a
1
+a
3
+...+a
21
=a
2
+a
4
+...+a
20
+15 tenglik o’rinli bo’lsa, a
11
ni toping.
A) 11 B) 13 C) 15 D) 17 E) 19
## a
1
+(a
3
-a
2
)+(a
5
-a
4
)+...+(a
21
-a
20
)=15; a
1
+10d=15; a
11
=15.
To’g’ri javob: C.
60(2002-4.41).
f x
x
x
( )
/
=
−
+ −
5
1 25
funksiyaning aniqlanish
sohasiga tegishli barcha butun sonlarning o’rta arifmetigini toping.
A) -2 B) -1 C) 0 D) 1 E) 2
##
5
1
25
0
0
x
x
−
≥
− ≥
⎧
⎨
⎪
⎩⎪
⇒
5
5
0
2
x
x
≥
≤
⎧
⎨
⎩
−
⇒
x
x
≥ −
≤
⎧
⎨
⎩
2
0
⇒ -2≤x≤0.
− + − +
= −
2
1
0
3
1
(
)
. To’g’ri javob: B.
61(2002-4.44).
1
2
+ ≤
+
x
x
arccos(
) tengsizlikning eng katta butun
yechimini toping.
A) -2 B) -1 C) 0 D) 1 E) 2
##
1
0
1
2
1
+ ≥
− ≤ + ≤
⎧
⎨
⎩
x
x
⇒
x
x
≥ −
− ≤ ≤ −
⎧
⎨
⎩
1
3
1
⇒ x= -1.
To’g’ri javob: B.
62(2002-5.14).
x
x
x
x
+ −
+
+
+ +
+
=
3
14
3
14
4 bo’lsa, x/( x+1)
ning qiymatini toping.
A) 2/3 B) -2/3 C) 3 D) 3/2 E) -3/2
##
x
t
+
=
14
deb belgilasak, x=t
2
-14 bo’ladi. Bundan
t
t
t
t
2
2
11
11
4
−
− +
−
+ = . Bu tenglamani yechsak: t
1,2
=
±4.
a)
x
+
= −
14
4
tenglama yechimga ega emas.
b)
x
+
=
14
4
; x+14=16; x=2. To’g’ri javob: A.
63(2002-6.14). Nechta natural ( x; y) sonlar jufti x
2
-y
2
=53 tenglikni
qanoatlantiradi?
A)
∅ B) 1 C) 2 D) 3 E) 4
## x
2
-y
2
=1
⋅53; (x-y)(x+y)=1⋅53
x
y
x
y
− =
+ =
⎧
⎨
⎩
1
53
⇒ x=27; y=26. (27;26) Bitta juftlik.
To’g’ri javob: B.
64(2002-6.20). log
( ,
)
log (
...)
128
1
3
1
9
1
27
0 25
6
+ +
+
⎛
⎝
⎜
⎞
⎠
⎟ ni hisoblang.
A) 2/7 B) 3/8 C) 1/14 D) 2/5 E) 1/12
##
1
3
1
9
1
27
+ +
+... - birinchi hadi
1
3
va mahraji
1
3
ga teng bo’lgan cheksiz
kamayuvchi geometrik progressiyaning yig’indisi.
1
3
1
9
1
27
+ +
+...=
1
2
.
Buni berilgan ifodaga qo’yamiz:
log
( ,
)
log
(
...)
128
1
3
1
9
1
27
0 25
16
+ +
+
⎛
⎝
⎜
⎞
⎠
⎟ = log ( / )
log (
)
log
( / )
log
/
128
1 2
2
2 1 2
1 4
1
7
4
16
4
=
=
=
1
7
2
1
7
1
2
2
1 2
log
/
= ⋅ =
1
14
. To’g’ri javob: C.
65(2002-2.46). Doiradan markaziy burchagi 90
° bo’lgan sektor qirqib
olingach, uning qolgan qismi o’ralib konus shakliga keltirildi. Bu konus
diametrining yasovchisiga nisbatini toping.
A) 3/2 B) 2 C) 5/4 D) 2/3 E) 4/5
## Konus asosining uzunligi
sektor yoyining uzunligiga, konusning
yasovchisi esa sektorning radiusiga teng.
C
konus
=1,5
πR
sektor
;
d
konus
=1,5
R
sektor
;
L
konus
=
R
sektor
D
konus
:l
konus
=1,5R:R=1,5=3/2.
66(2002-3.57). To’g’ri burchakli uchburchakning
α va β o’tkir burchaklari
uchun cos
α+sin(α-β)=1 tenglik o’rinli bo’lsa, β ning qiymatini toping.
A) 30
° B) 45° C) 60° D) 75° E) aniqlab bo’lmaydi.
##
α+β=90° dan α=90°-β bo’ladi.
cos
α+sin(α-β)=cos(90°-β)+sin(90°-2β)=sinβ+cos2β=sinβ+1-2sin
2
β.
sin
β+1-2sin
2
β=1; 2sin
2
β-sinβ=0; sinβ(2sinβ-1)=0;
sin
β=0 bo’la olmaydi, shuning uchun 2sinβ-1=0; β=30°.
To’g’ri javob: A.
67(2002-4.49). Uchburchakning burchaklari 1:2:3 kabi nisbatda.
Uchburchak katta tomonining kichik tomoniga nisbatini toping.
A) 1 B) 2 C) 3 D) 4 E) 5
##
∠A:∠B:∠C=1:2:3 dan ∠A=30°; ∠B=60°; ∠C=90°.
c=a/sinA= a/sin30
°=a/0,5=2a. c:a=2a:a=2. To’g’ri javob: B
68(2002-4.50). Uchburchakning tomonlar 10, 13 va 17 ga teng. Bu
uchburchakka tashqi chizilgan aylananing markazi qayerda bo’lishini
aniqlang.
A) uchburchak ichida B) uchburchakning kichik tomonida
C) uchburchak tashqarisida D) aniqlab bo’lmaydi
E) uchburchakning katta tomonida
## 10
2
+13
2
<17
2
bo’lgani uchun bu uchburchak o’tmas burchakli. O’tmas
burchakli uchburchakka tashqi chizilgan aylananing markazi uchburchak
tashqarisida joylashadi.
To’g’ri javob: C.
69(2002-4.52). Piramidaning asosi gipotenuzasining uzunligi 2 bo’lgan
to’g’ri burchakli uchburchakdan iborat. Piramidaning qirralari asos
tekisligi bilan
α burchak tashkil qiladi. Agar uning balandligi 5 ga teng
bo’lsa,
tg
α ning qiymatini toping.
A) 1 B) 2 C) 3 D) 4 E) 5
## Piramidaning barcha yon qirralari asos tekisligiga bir xil og’ishganda
piramida balandligining asosi, piramida asosiga tashqi chizilgan aylana
markazi bilan ustma-ust tushadi. Piramida asosi to’g’ri burchakli
uchburchak bo’lgani uchun balandlikning asosi gipotenuzaning o’rtasida
yo’tadi. Shunday qilib, tg
α=5/1=5. To’g’ri javob: E.
70(2003-1.8).
2
3
4
2
−
+
> −
x
x
tengsizlikning eng kichik butun yechimini
toping.
A) 0 B) -1 C) -2 D) -3 E) -5
## Arifmetik kvadrat ildizning qiymati doimo nomanfiy son bo’lgani
uchun, bu tengsizlik
2
3
4
0
−
+
≥
x
x
tengsizlikka teng kuchli. Bundan
(2-3x)(x+4)
≥0
-4 2/3
(-4; 2/3]
Eng kichik butun yechimi: -3. To’g’ri javob: D.
71(2003-1.52).
x
x
dx
+
∫
1
1
2
ni hisoblang.
A) 2+ln(1/2) B) 1+ln(2/3) C) 3-ln(2/3) D) 1-ln(2/3) E) 2-ln(2/3)
##
x
x
dx
+
∫
1
1
2
=
(
)
x
x
dx
+ −
+
∫
1
1
1
1
2
=
(
)
1
1
1
1
2
−
+
∫
x
dx
= (x-ln(x+1))⏐
1
2
=
=(2-ln(2
+1))-(1-ln(1+1))=2-ln3-1+ln2=1+ln(2/3). To’g’ri javob: B.
72(2003-6.5). Agar
29
31
38
41
47
51
+
+
= a
bo’lsa,
2
31
3
41
4
51
+
+
quyidagi-
larning qaysi biriga teng?
A) 3-
a B) 4- a C) 5- a D) 3- a/2 E) 4- a/2
##
2
31
3
41
4
51
+
+
=
31 29
31
41 38
41
51 47
51
−
+
−
+
−
=
1
29
31
1
38
41
1
47
51
−
+ −
+ −
=
3-(
29
31
38
41
47
51
+
+
)=3-
a. To’g’ri javob: A.
73(2003-6.15).
x
x
x
+
+
+
=
...
3
3
3
4 tenglamani yeching.
A) 56 B) 48 C) 60 D) 54 E) 64
## Har ikki qismini kubga ko’taramiz:
x
x
x
x
+
+
+
+
=
...
3
3
3
64 .
x
x
x
+
+
+
=
...
3
3
3
4 ni e’tiborga olsak,
x+4=64 bo’ladi.
Bundan
x=60. To’g’ri javob: C
74(2003-6.26). Agar
sin37
°=a bo’lsa, sin16° ni a orqali ifodalang.
A)
a
2
B)
a-1 C) 2 a
2
-1 D) 1-2 a
2
E) aniqlab bo’lmaydi.
## sin37
°=sin(45°-8°)=sin45°cos8°-cos45°sin8°=
2
2
cos8
°-
2
2
sin8
°=
=
2
2
(cos8
°-sin8°). Demak:
2
2
(cos8
°-sin8°)=a; cos8°-sin8°=
2
a;
(cos8
°-sin8°)
2
=(
2
a)
2
; cos
2
8
°-2cos8°sin8°+sin
2
8
°=2a
2
.
Bundan sin16
°=1-2a
2
. To’g’ri javob: D.
75(2003-7.30). Agar f(x)=
7
2
x
ax
b
x
+
+
funksiya grafigi (2;0) nuqtada
absissalar o’qiga urinib o’tsa, a+b nimaga teng?
A) 0 B) 20 C) -21 D) 28 E) -56
## Shartga ko’ra f(2)=0 bo’lishi kerak, shuning uchun:
7 2
2
2
0
2
⋅
+ ⋅ +
=
a
b
. Bundan b= -2a-28.
Ikkinchi tomondan urinma OX o`qiga parallel (aniqrog’i OX o`qining o’zi)
bo’lgani uchun f
′
(2)=0
bo’lishi kerak. Shuning uchun
(
)
14
7
0
2
2
x
a x
x
ax
b
x
+
−
−
−
=
14
7
0
2
2
x
ax
x
ax
b
+
−
−
− =
a
=-28
b
=-28-2
⋅(-28)=28
a
+b=-28+28=0.
To’g’ri javob: A.
76(2003-8.34). Agar
x
y
xy
x
y
xy
+ −
=
+
+
=
⎧
⎨
⎪
⎩⎪
7
133
2
2
bo’lsa, xy ning qiymatini
toping.
A) 36 B) 42 C) 25 D) 81 E) 16
⎪⎩
⎪
⎨
⎧
+
=
+
+
=
+
xy
y
x
xy
y
x
133
)
(
7
2
=>
xy
xy
+
=
+
133
)
7
(
=>
xy
xy
xy
+
=
+
+
133
14
49
6
=
xy
xy=36.
To`g`ri javob: A
77(2003-8.40).
xy
x
y
yz
y
z
xz
x
z
+
=
+
=
+
=
⎧
⎨
⎪
⎪
⎪
⎩
⎪
⎪
⎪
10
7
40
13
5
8
tenglamalar sistemasidan x ni toping.
A) 80/79 B) 5/7 C) 7/13 D) 79/80 E) 7/5
## Tenglamalar sistemasini quyidagicha qayta yozamiz:
x
y
xy
y
z
yz
x
z
xz
+
=
+
=
+
=
⎧
⎨
⎪
⎪
⎪
⎩
⎪
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