Upload
peter-dan-thy
View
217
Download
0
Embed Size (px)
Citation preview
7/31/2019 Chuyn 1. Phng trnh i s - bt phng trnh i s
1/8
Chuyen e 1: PHNG TRNH AI SO& BAT PHNG TRNH AI SO
TOM TAT GIAO KHOACAC HANG ANG THC C BAN
1. ( ) + = + +2 2 22a b a ab b22a b a ab b
)a b a b33 3a b a a b ab b33 3a b a a b ab b
)b a b a ab b
)a b a ab b
abbaba 22)(22 +=+
2. ( ) = +2 2 abbaba 22)(22 +=+
3. a b = + 2 2 ( )(
4. ( ) + = + + +3 3 2 2 )(33)(33 baabbaba ++=+
5. ( ) = + 3 3 2 2
6. a + = + +3 3 2 2( )(
7. a b = + +3 3 2 2( )(
Ap dung:Biet va . Hay tnh cac bieu thc sau theo S va PSyx =+
+= 4xD
Pxy =
d 2) ya += 2xA 2y)-(xB =)b 3) yc += 3xC 4) y
A. PHNG TRNH AI SO
I. Giai va bien luan phng trnh bac nhat:
1. Dang : ax + b = 0 (1)
sotham:ba,
soan:x
2. Giai va bien luan:
1
Ta co : (1) ax = -b (2)
Bien luan:
Neu a 0 th (2) a
bx =
Neu a = 0 th (2) tr thanh 0.x = -b* Neu b 0 th phng trnh (1) vo nghiem* Neu b = 0 th phng trnh (1) nghiem ung vi moi x
Tom lai :
a 0 : phng trnh (1) co nghiem duy nhata
bx =
a = 0 va b 0 : phng trnh (1) vo nghiem a = 0 va b = 0 : phng trnh (1) nghiem ung vi moi x
7/31/2019 Chuyn 1. Phng trnh i s - bt phng trnh i s
2/8
Ap dung:V du : Giai va bien luan cac phng trnh sau:
mxmx 222 +=+
3. ieu kien ve nghiem so cua phng trnh:
nh ly: Xet phng trnh ax + b = 0 (1) ta co:
(1) co nghiem duy nhat a 0 (1) vo nghiem
=
0
0
b
a
(1) nghiem ung vi moi x
=
=
0
0
b
a
Ap dung:V du : Vi gia tr nao cua a, b th phng trnh sau nghiem ung vi moi x
0)1(24
=++ bxaxaII.Giai va bien luan phng trnh bac hai:
1. Dang: 2 0ax bx c+ + = (1)
sotham:c,ba,
soan:x
2. Giai va bien luan phng trnh :
Xet hai trng hpTrng hp 1
2
: Neu a th (1) la phng trnh bac nhat : bx + c = 00=
b 0 : phng trnh (1) co nghiem duy nhat bcx = b = 0 va c 0 : phng trnh (1) vo nghiem b = 0 va c = 0 : phng trnh (1) nghiem ung vi moi x
Trng hp 2: Neu a 0 th (1) la phng trnh bac hai co
Biet so ( hoac2 4b a = c ' 2 '' vi b2
bb ac = = )
Bien luan:) Neu th pt (1) vo nghiem0