(Viet teoremasi);
1 2 a 1 2 a
2. ax2 bx c a(x x1)(x x2 ) ;
2 2 2
b2 2ac
3. x1 x2 x1 x2
3
2x1x2 a2 ;
b 3 3bc
4. x3 x3 x x 3x x (x x ) ;
1 2 1 2 1 2 1 2
a
a2
1 1 b2 2ac 1 1 b3 3abc
5. x2 x2 c2 ; x3 x3 c3 ;
1 2 1 2
b 2
b2 4ac
6. to‘la kvadratga ajratish:
ax2 bx c a x
2a 4a .
Agar
x1,
x2,
Kub tenglama
x3 ax2 bx c 0 .
x3 lar bu tenglamaning ildizlari bo‘lsa, u holda
1. x3 ax2 bx c (x x1)(x x2 )(x x3 ) .
x1 x2 x3 a,
2. Viet teoremasi: x x x x x x b,
1 2 1 3 2 3
x x x c.
1 2 3
Ikki noma’lumli chiziqli tenglamalar sistemasi
Umumiy ko‘rinishi:
a11x a12 y b1,
a x a y b .
Geometrik talqini
Agar
a11 a21
a12
a22
b1 b2
21 22 2
bo‘lsa,
sistema yechimga ega emas.
Agar
a11 a21
a12
a22
bo‘lsa,
sistema yagona yechimga ega.
Agar
a11 a21
a12
a22
b1 b2
bo‘lsa,
sistema cheksiz ko‘p yechimga ega.
Arifmetik progressiya
an1 an d ,
n 0, 1, 2,... .
bu yerda
a1 – birinchi hadi, d –ayirmasi.
ayirmasini topish:
d an1
an am , n m ;
n m
n - hadini topish:
an a1 n 1 d ;
o‘rta hadini topish:
a an k an k n 2
, k n ;
dastlabki n ta hadining yig‘indisini topish:
S a1 an n 2a1 n 1 d n ;
n 2 2
n - dan k - gacha bo‘lgan hadlar yig‘indisini topish:
Sk a dn(k 1) k n ;
an Sn Sn1 .
n n
Geometrik progressiya bn1 bnq, n 1, 2, 3,... .
bu yerda,
b1 – birinchi hadi, q – maxraji.
maxrajini topish:
n - hadini topish:
q bn1 ;
bn
bn b1 qn1, bn bnm qm ;
o‘rta hadini topish:
bn ;
dastlabki n ta hadi yig‘indisini topish:
b q b
b1 qn 1
bn Sn Sn1 ;
Sn
n 1
q 1
q 1 ;
Cheksiz kamayuvchi geometrik progressiya hadlari yig‘indisi:
S b1 ,
1 q
q 1.
Tengsizliklarning xossalari
Agar
f ( x) g( x) bo‘lsa,
c 0 da cf ( x) cg( x) ,
c 0 da cf ( x) cg( x)
bo‘ladi.
Agar bo‘ladi.
f 2n ( x) g 2n ( x) f 2n( x) g2n ( x)
bo‘lsa, u holda
f ( x) g( x) f ( x) g( x)
Agar o‘rinli.
f ( x) c f ( x) c
bo‘lsa, u holda c f ( x) c
f (x) c ёки
f (x) c
lar
1. f (x) 0
g(x)
Kasr ratsional tenglama va tengsizliklar
f (x) 0,
g(x) 0.
2. f (x) h(x)
f (x)v(x) g(x)h(x) 0,
g(x) v(x)
g(x)v(x) 0.
3. f (x) 0
g(x)
f (x)
f (x)g(x) 0,
g(x) 0.
f (x) g(x)h(x) g(x) 0,
4. h(x) g(x)
g(x) 0.
Agar a b c d
bo‘lsa, u holda
Oraliqlar usuli
a) (x a)(x b)(x c)(x d) 0
bo‘ladi.
tengsizlikning yechimi (;a) (b;c) (d;)
b) (x a)(x b)(x c)(x d ) 0
Bu usul oraliqlar usuli deyiladi.
tengsizlikning yechimi (a;b) (c;d )
bo‘ladi.
Kvadrat tengsizlik
ax2 bx c 0 ax2 bx c 0
1) a 0, D 0 bo‘lsa,
|
x ; x1 x2;
|
x x1; x2 ;
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2) a 0, D 0 bo‘lsa,
|
x ;
|
x x1 ;
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3) a 0, D 0 bo‘lsa,
|
x ;
|
x ;
|
4) a 0, D 0 bo‘lsa,
|
x x1; x2
|
; x1 x2 ; ;
|
5) a 0, D 0
bo‘lsa,
x x1
x ; ;
6) a 0, D 0
bo‘lsa, x
x ; .
Irratsianal tenglama va tengsizliklar
1. 2k f (x) 0
f (x) 0 .
g(x) 0,
2k
f (x) g x
f ( x) g 2k
(x).
2k
f (x) 2k g x
f ( x) 0,
f (x) g(x).
4. 2k1 f (x) g x
f (x) g 2k1(x) .
f (x) 0, g(x) 0,
5. 2 k
f (x) g x
f ( x) g 2k
(x).
6. 2k1 f (x) g x
f (x) g 2k1(x) .
g(x) 0,
g(x) 0,
7. 2 k
f (x) g x
f ( x) g 2k
(x).
ёки
f ( x) 0.
8. 2k1 f (x) g x
f (x) g 2k1(x) .
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