76
77
130.
Funksiyaning lokal maksimum va lokal mimimumlarini toping:
1)
( )
4
2
4
1
x
x
x
f
−
=
;
2)
( )
2
3
14 13
12
f x
x
x
=
+
−
;
3)
( )
9
3
2
3
4
+
+
−
=
x
x
x
x
f
;
4)
( )
7
2
3
4
+
−
=
x
x
x
f
.
131.
Funksiyaning o‘sish, kamayish oraliqlari hamda lokal maksimum
va minimumlarini toping:
1)
f
(
x
)=
x
3
– 64
x
; 2)
f
(
x
) = 2
x
3
–24; 3)
f
(
x
)=4
x
3
–108
x
.
132.
Funksiyaning eng katta va eng kichik qiymatlarini toping:
1)
( )
2
3
2
4
+
−
=
x
x
x
f
,
x
∈[
–
4; 1]
; 2)
( )
1
6
3
5
+
+
=
x
x
x
f
,
x
∈[
–
1; 2]
;
3)
( )
4
+
=
x
x
x
f
,
x
∈[1; 5]
; 4)
( )
8
5
6
2
3
+
+
+
=
x
x
x
x
f
,
x
∈[
–
3; 4].
133.
Funksiyaning grafigini yasang:
1)
;
2
3
2
2
3
−
+
−
=
x
x
x
y
2)
3
5
3
2
5
1
x
x
y
+
=
; 3)
3
4
4
x
x
y
+
=
.
134.
To‘g‘r
i to‘rtburchak shaklidagi ekin maydonining atrofini o‘rash
uchun 1000 metr
panjara sotib olindi. Bu panjara yordamida eng ko‘pi
bilan necha kvadrat metr
maydonni o‘rab olish mumkin?
135.
Tomoni 16 dm bo‘lgan kvadrat shaklidagi kartondan usti ochiq
quti tayyorlandi. Bunda kartonning uchlaridan bir xil kvadratchalar
kesib olindi. Qutining hajmi eng katta bo‘lishi uchun uning asosi necha
santimetr bo‘lishi kerak?
136*.
Konserva banka silindr shaklida bo‘lib, uning to‘la sirti 512π cm
2
ga
teng. Bankaga eng ko‘p suv sig‘ishi uchun banka asosining radiusi va
balandligi qanday bo‘lishi kerak?
137.
To‘g‘ri to‘rtburchak shaklidagi maydoning yuzi 3600 m
2
. Maydonning
tomonlari qanday bo‘lganda uni o‘rash uchun eng kam panjara zarur
bo‘ladi?
138*.
Radiusi 8 dm bo‘lgan sharga eng kichik hajmli konus tashqi chizilgan.
Shu konus balandligini toping.
139*.
Asosi kvadrat bo‘lgan to‘g‘ri burchakli parallelepiped shaklidagi ochiq
metall idishga 32
l
suyuqlik ketadi. Idishning o‘lchamlari qanday
bo‘lganda uni yasashga eng kam metall sarflanadi?
76
77
140.
Moddiy nuqta
( )
4
3
10
4
t
s t
t
= −
+
qonuniyat bilan harakatlanmoqda
(
s
(
t
) metrda
, t
sekundda o‘lchanadi).
1) eng katta tezlanishga erishadigan (
t
0
) vaqtni;
2)
t
0
vaqtdagi oniy tezlikni;
3)
t
0
vaqtda bosib o‘tilgan yo‘lni toping.
141.
Havo shariga
t
∈
[0;10] minut oralig‘da
V
(
t
) =
t
3
+3
t
2
+2
t
+4 m
3
havo
purkalmoqda.
1) boshlang‘ich vaqtdagi havo hajmini;
2)
t
= 10 minutdagi havo hajmini;
3)
t
= 5 minutdagi havo purkash tezligini toping.
142.
Akrom shim tikish uchun buyurtma oldi. Bir oyda
x
ta shim tiksa,
p
(
x
) = – 2
x
2
+240
x
(ming so‘m) daromad qiladi.
1) daromadni eng katta qilish uchun qancha shim tikish kerak?
2) eng katta daromad necha so‘m bo‘ladi?
143
.
Funksiyaning hosilasini toping:
1)
x
e
y
3
=
; 2)
x
e
y
sin
=
; 3)
(
)
2
3
sin
+
=
x
y
; 4)
(
)
4
1
2
+
=
x
y
;
5)
1
2
2
+
−
=
x
x
y
; 6)
ln
x
y
x
=
; 7)
y
= arctg2
x
; 8)
x
e
x
x
y
⋅
⋅
=
cos
2
.
144.
( )
x
e
x
f
2
=
va
( )
2
4
+
=
x
x
g
funksiyalar uchun
( )
x
F
murakkab
funksiyani tuzing:
1)
( )
( )
(
)
x
g
f
x
F
=
;
2)
( )
( )
( )
x
g
x
f
x
F
=
;
3)
( )
( )
(
)
x
f
g
x
F
=
;
4)
( )
( )
(
)
x
g
g
x
F
=
.
145.
Murakkab funksiyaning hosilasini toping:
1)
(
)
5
2
1
+
=
x
y
; 2)
y
=lncos
x
;
3)
7
5
−
=
x
y
; 4)
(
)
tg 2
3
y
x
=
−
;
5)
y=
arctg(3
x
–4);
6*)
y=
sin(arctg2
x
);
7)
x
x
y
3
3
cos
sin
+
=
;
8*)
(
)
x
e
y
cos
sin
=
.
78
79
146.
Funksiyaning o‘sish va kamayish oraliqlarini toping:
1)
2
2
x
x
y
−
+
=
; 2)
(
)
0
100
≥
+
=
x
x
x
y
;
3)
3
3
x
x
y
−
=
;
4)
x
x
y
sin
2
−
=
;
5)
2
1
2
x
x
y
+
=
;
6)
x
x
y
2
2
=
;
7)
(
)
3
1
−
=
x
y
;
8)
(
)
4
1
−
=
x
y
.
147.
Funksiyaning statsionar nuqtalari, lokal maksimum va lokal mini-
mumlarini toping:
1)
4
9
6
2
3
−
+
−
=
x
x
x
y
; 2)
2
1
2
x
x
y
+
=
;
3)
x
x
y
1
+
=
;
4)
2
2
x
x
y
−
=
.
148.
Funksiyaning ko‘rsatilgan oraliqdagi eng katta va eng kichik qiy-
matlarini toping:
1)
( )
x
x
f
2
=
,
[
]
5
;
1
−
; 2)
( )
6
4
2
+
−
=
x
x
x
f
, [–3; 10];
3)
( )
x
x
x
f
1
+
=
, [0,01; 100]; 4)
( )
x
x
f
4
5
−
=
,
[
]
1
;
1
−
;
5)
( )
x
x
f
cos
=
,
;
2
π
−
π
; 6)
( )
2
3
2
+
−
=
x
x
x
f
, [–10; 10];
7)
( )
x
x
f
cos
=
sin
x
,
;
2
π
π
; 8)
( )
2
3
2
+
−
=
x
x
x
f
+
( )
2
3
2
+
−
=
x
x
x
f
, [–15; 10].
149.
Funksiyani tekshiring va grafigini yasang:
1)
3
3
x
x
y
−
=
;
2)
2
1
4
2
x
x
y
−
+
=
;
3)
(
)(
)
2
2
1
−
+
=
x
x
y
;
4)
1
y x
x
= +
;
5)
2
16
y
x
=
−
;
6)
2
9
y
x
=
−
;
7)
2
5
6
y x
x
=
−
+
;
8)
4
2
1
1
4
2
y
x
x
=
−
.
78
79
II BOB. INTEGRAL VA UNING TATBIQLARI
37–39
BOSHLANG‘ICH FUNKSIYA VA ANIQMAS
INTEGRAL TUSHUNCHALARI
Agar nuqta harakat boshlanganidan boshlab
t
vaqt mobaynida
s
(
t
)
masofani o‘tgan bo‘lsa, uning oniy tezligi
s
(
t
) funksiyaning hosilasiga teng
ekanini bilasiz:
v
(
t
)=
s
'(
t
). Amaliyotda
teskari masala:
nuqtaning berilgan
harakat tezligi
v
(
t
) bo‘yicha uning bosib o‘tgan yo‘li
s
(
t
) ni topish masalasi
ham uchraydi. Shunday
s
(
t
) funksiyani topish kerakki, uning hosilasi
v
(
t
)
bo‘lsin. Agar
s
'(
t
)=
v
(
t
) bo‘lsa,
s
(
t
) funksiya
v
(
t
) funksiyaning
boshlang‘ich
funksiyasi
deyiladi. Umuman, shunday ta’rif kiritish mumkin:
Agar (
a
;
b
) ga tegishli ixtiyoriy
x
uchun
F
′(
x
)=
f
(
x
) bo‘lsa,
F
(
x
)
funksiya (
a
;
b
) oraliqda
f
(
x
) ning
boshlang‘ich funksiyasi
deyiladi.
1-misol.
a
– berilgan biror son va
v
(
t
)=
at
bo‘lsa,
2
1
( )
2
s t
at
=
funksiya
v
(
t
) funksiyaning boshlang‘ichidir, chunki
s
2
( ) (
)
( ).
2
at
s t
at v t
′
′
=
=
=
2-misol.
f
(
x
)
=x
2
, x
∈
(– ∞; ∞), bo‘lsa,
3
1
( )
3
F x
x
=
funksiya
f
(
x
)
ning
(– ∞; ∞) dagi bo
shlang‘ich funksiyasi bo‘ladi, chunki
F
3
2
2
1
1
( ) (
)
3
( ).
3
3
F x
x
x
x
f x
′
=
= ⋅
=
=
ʹ
3
2
2
1
1
( ) (
)
3
( ).
3
3
F x
x
x
x
f x
′
=
= ⋅
=
=
3-misol.
2
1
( )
,
cos
f x
x
=
bunda
,
2
x
k
π
≠ + π
k
∈
Z
,
funksiya uchun
F
(
x
)=tg
x
boshlang‘ich funksiya bo‘ladi, chunki (tg
x
)'
1
2
1
( )
.
cos
tgx
x
=
4-misol.
1
( )
,
f x
x
=
x
>0, bo‘lsa,
F
(
x
)
=
ln
x
funksiya
1
x
ning boshlang‘ich
|