7 - § DARAJA QATNASHGAN TENGLAMAVA TENGSIZLIKLAR.
1. 7 soni tenglamaning ildizi bo'lishini ko'rsating:
1)
= 2; 2)
= 3.
2. Tenglamani yeching:
1)
=3; 2)
= 7; 3)
= 0; 4)
Tenglamani yeching (3 - 4):
3
. 1)
= 2; 2)
= 3;
3)
= 4 ; 4)
= 3.
4.
1)
; 2)
;
3)
; 4)
.
5.
1)
= x
; 2)
;
3)
; 4)
.
6.
1)
; 2)
.
7. Berilgan tenglama nima uchun ildizlarga ega emasligini tushuntiring:
1)
=
- 8 ; 2)
+
= - 3;
3)
= 12; 4)
= 5 .
Tenglamani yeching (8 - 10):
8.
1)
; 2)
= 3x + 8;
3) 2x = 1 +
; 4)
9.
1)
; 2)
10.
1)
; 2)
;
35
3)
; 4)
11. x ning qanday qiymatlarida funksiyalar bir xil qiymatlarni qabul qiladi:
1)
,
; 2)
?
8 - §. ARIFMETIK PROGRESSIYA
Ta`rif .
Arifmetik progressiya deb shunday ketma-ketlikka aytiladiki, unda ikkinchi hadidan
boshlab har bir hadi avvalgi hadiga ayni bir sonni qo`shish bilan hosil qilinadi.
Boshqacha aytganda
Agar a
1
, a
2
, ... , a
n
, ... sonli ketma-ketlikda barcha natural n lar uchun
a
n+1
=
a
n
+ d (bunda d -
biror son) tenglik bajarilsa, bunday ketma-ketlik arifmetik progressiya deyiladi.
Bu formuladan
a
n+1
- a
n
= d
ekanligi kelib chiqadi.
d
son
arifmetik progressiyaning ayirmasi
deyiladi.
Shunday qilib, arifmetik progressiyaning ikkinchi hadidan boshlab, har bir hadi unga qo'shni
bo'lgan ikkita hadning o'rta arifmetigiga teng. progressiya degan nom shu bilan izohlanadi.
1.
2
1
1
n
n
n
a
a
a
2.
q
p
m
k
a
a
a
a
q
p
m
k
,
Arifmetik progressiyaning ayirmasi formulasi
1.
a
-
a
d
1
-
n
n
Arifmetik progressiyaning n-hadi formulasi
1.
d
n
a
a
n
1
1
2
.
d
a
a
n
n
1
S
n
- arifmetik progressiya dastlabki n ta hadining yig'indisi:
1
.
S
n
= a
1
+ a
2
+ ... + a
n-1
+ a
n
.
2.
n
a
a
S
n
n
2
1
3.
n
d
n
a
S
n
2
1
2
1
4.
a
n
= S
n
– S
n – 1
Mashqlar
1.
Arifmetik progressiyaning birinchi hadini va ayirmasini ayting:
1) 6, 8, 10, ...; 2) 7, 9, 11,...; 3) 25, 21, 17,...; 4) -12, -9, -6, ... .
2. Agar arifmеtik progrеssiyada
1)
2
1
a
va
5
d
bo`lsa uning beshinchi hadini toping.
2)
3
1
a
va
5
d
bo`lsa uning yettinchi hadini toping.
3)
3
1
a
va
2
1
d
bo`lsa a
8
ni toping.
3. Agar arifmеtik progrеssiyada
1)
2
1
a
va
3
d
bo`lsa
15
a
ni toping.
2)
3
1
a
va
4
d
bo`lsa
20
a
ni toping.
3)
3
1
a
va
2
d
bo`lsa
18
a
ni toping.
4)
a
1
=
-2,
d =
- 4 bo'lsa,
a
11
ni toping.
36
4. arifmеtik progrеssiyaning n - chi hadi formulasini yozing.
1) 1, 6, 11, 16,….;
2) 25, 21, 17, 13,….; 3) 1, -4, -9, -14,….;
5.
1) – 22 soni 44, 38, 32,….; arifmеtik progrеssiyaning hadi bo`lsa, shu sonning
nomеrini toping.
2) – 12 soni -18, -15, -12,….; arifmеtik progrеssiyaning hadi bo`ladimi.
3) – 59 soni 1, -5,….; arifmеtik progrеssiyaning hadi bo`lsa, shu sonning nomеrini
toping.
6. Agar arifmеtik progrеssiyada
1)
7
1
a
,
67
16
a
2)
4
1
a
,
0
9
a
3)
2
2
a
,
68
16
a
bo`lsa, uning ayirmasini toping.
7.
Arifmetik progressiyaning ayirmasi 1,5 ga teng. Agar:
1)
a
9
= 12; bo'lsa,
a
1
ni toping.
2)
a
7
=
- 4 bo'lsa,
a
1
ni toping.
8. Agar arifmеtik progrеssiyada
1)
3
d
,
20
11
a
2)
10
21
a
,
5
,
5
22
a
3)
2
d
,
23
11
a
bo`lsa, uning birinchi hadini toping.
9.
Agar arifmetik progressiyada:
1) a
3
= 13, а
6
= 22; 2) а
2
= -7, а
7
= 18
bo'lsa, uning
n-
hadi formulasini toping.
10.
n
ning qanday qiymatlarida 15, 13, 11, ... arifmetik progressiyaning hadlari manfiy bo'ladi?
11.
Arifmetik progressiyada
a
1
= -10, d = 0,5 bo'lsa,
n
ning qanday qiymatlarida
a
n
<
2 tengsizlik
bajariladi?
12.
Agar arifmetik progressiyada:
1) a
8
= 126, a
10
= 146; 2) a
8
= - 64, a
10
= - 50;
3) a
8
= -7, a
10
= 3; 4) a
8
=
0,5, a
10
= - 2,5.
bo'lsa, uning to'qqizinchi hadini va ayirmasini toping.
13. Agar arifmеtik progrеssiyada
1)
5
5
a
,
23
7
a
, bo`lsa, uning oltinchi hadini toping.
2)
126
8
a
,
146
10
a
, bo`lsa, uning to`qqizinchi hadini toping.
3)
22
11
a
,
36
13
a
, bo`lsa, uning o`n ikkinchi hadini toping.
14. Agar arifmеtik progrеssiyada
1) a
1
= 1, a
n
= 20, n = 50; 2) a
1
= 1, a
n
= 200, n = 100;
3) a
1
= -1, a
n
= -40, n = 20; 4) a
1
= 2, a
n
= 100, n = 50
bo`lsa, uning dastlabki n ta hadi yigindisini toping.
15. Agar arifmеtik progrеssiyada
1)
5
,
0
,
5
1
d
a
bo`lsa, uning dastlabki o`n ikkita hadi yigindisini toping.
2)
3
,
5
,
0
1
d
a
bo`lsa, uning dastlabki o`n ikkita hadi yigindisini toping.
3)
11
n
bo`lsa, 9, 13, 17,… uning dastlabki n ta hadi yigindisini toping.
4)
12
n
bo`lsa, -16, -10, -4,… uning dastlabki n ta hadi yigindisini toping.
5)
1050
,
14
,
10
14
1
S
n
a
bo`lsa, uning a
n
va d ni toping.
6)
6
5
90
,
10
,
3
1
2
10
1
S
n
a
bo`lsa, uning a
n
va d ni toping.
7)
210
,
21
7
7
S
a
bo`lsa, uning a
1
va d ni toping.
37
8)
22
,
21
11
11
S
a
bo`lsa, uning a
1
va d ni toping.
9) 1 dan 100 gacha bo`lgan natural sonlar yigindisini toping.
10) 1 dan 100 gacha bo`lgan toq sonlar yigindisini toping.
11) 2 dan 106 gacha bo`lgan juft sonlar yigindisini toping.
12) 2 dan 98 gacha bo'lgan barcha natural sonlar yig'indisini toping .
13)
1 dan 133 gacha bo'lgan barcha toq sonlarning yig'indisini toping .
14) Arifmеtik progrеssiyaning sakkizinchi hadi 26 ga tеng uning dastlabki 15
ta hadi yigindisini toping.
15) Arifmеtik progrеssiyaning yigirmanchi hadi 125 tеng uning dastlabki 39
ta hadi yigindisini toping.
16) Arifmеtik progrеssiya n - hadining formulasi bilan bеrilgan. Agar
1)
5
3
n
a
n
2)
7
2
n
a
n
3)
8
5
n
a
n
bo`lsa,
50
S
ni toping.
16.
1) agar n = 11 bo'lsa, 9; 13; 17;...; 2) agar n = 12 bo'lsa, -16; -10; - 4;...
arifmetik progressiyaning dastlabki n ta hadi yig'indisini toping.
17.
Agar:
1) 3 + 6 + 9 + ... + 273; 2) 90 + 80 + 70 + ... + (-60)
yig'indining qo'shiluvchilari arifmetik progressiyaning ketma- ket hadlari bo'lsa, shu yig'indini toping.
18.
1) Barcha ikki xonali sonlar yig'indisini toping.
2) Barcha uch xonali juft sonlar yig'indisini toping.
19.
Yig'indi 75 ga teng bo'lishi uchun, 3 dan boshlab nechta ketma- ket natural sonni qo'shish kerak?
20.
Agar arifmetik progressiyada:
1) a
1
= 10, n = 14, S
14
=1050; 2)
6
5
90
,
10
,
3
1
2
10
1
S
n
a
bo'lsa, a
n
va d ni toping. bo'lsa, a
n
va d ni toping.
21.
Agar arifmetik progressiyada:
1) a
7
= 21, S
7
= 210; 2) a
11
= 92, S
11
= 22
bo'lsa, a
1
va d ni toping. bo'lsa, a
1
va d ni toping.
22.
Arifmetik progressiyada a
3
+ a
9
= 8. S
11
ni toping.
23.
Agar arifmetik progressiyada S
5
= 65 va S
10
= 230 bo'lsa, uning birinchi hadini va ayirmasini toping.
9 - §. Gеomеtrik progrеssiya.
Ta`rif.
Gеomеtrik progrеssiya deb, noldan farqli sonlarning shunday ketma-ketligiga aytiladiki,
unda ikkinchi hadidan boshlab har bir hadi avvalgi hadni ayni bir songa ko`paytirilganiga teng .
Boshqacha aytganda, agar istalgan natural n uchun
1.
q
b
b
va
b
n
n
n
1
0
shart bajarilsa,
n
b
ketma-ketlik gеomеtrik progrеssiya bo`ladi.
q
soni gеomеtrik progrеssiyaning maxraji deyiladi.
2.
n
n
b
b
q
1
Gеomеtrik progrеssiyaning n – hadi formulasi
3.
1
1
n
n
q
b
b
38
Agar progressiyaning barcha hadlari musbat bo'lsa, u holda
1
1
n
n
n
b
b
b
bo'ladi,
ya'ni geometrik progressiyaning ikkinchisidan boshlab, har bir hadi unga qo'shni bo'lgan ikkita hadning
o'rta geometrigiga teng. progressiya degan nom shu bilan izohlanadi.
4.
1
1
2
n
n
n
b
b
b
5.
q
p
m
k
b
b
b
b
q
p
m
k
,
S
n
- geometrik progressiya dastlabki n ta hadining yig'indisi:
6
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