chuyeân ñeà 2: phÖÔng trÌnh vaØ baÁt
TRANSCRIPT
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8/14/2019 Chuyen e 2: Phng Trnh Va Bat
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Chuyen e 2:PHNG TRNH VA BAT PHNG TRNH
CHA GIA TR TUYET OITOM TAT GIAO KHOA
I. nh ngha va cac tnh chat c ban :neu x 0( x )
neu x < 0
=
x1. nh ngha:
11
x Rx
2. Tnh chat : 2 20 , x =x x a b a b+ + a b a b + . 0a b a b a b+ = + . 0a b a b a b = +
II. Cac nh ly c ban :
a) nh ly 1 : Vi A 0 va B 0 th : A = B A2 = B2
b) nh ly 2 : Vi A 0 va B 0 th : A > B A2 > B2
III. Cac phng trnh va bat phng trnh cha gia tr tuyet oi c ban & cach giai :
* Dang 1 : 22 BABA == , BABA ==
* Dang 2 :
=
=
22
0
BA
BBA ,
=
=
BA
BBA
0,
=
> , 0))(( >+> BABABA
* Dang 4:2
B 0A B
A B
><
<
<
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8/14/2019 Chuyen e 2: Phng Trnh Va Bat
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* Dang 5:
>
22
0
0
BA
B
B
BA ,
B 0
A B B 0
A B A
B< >
IV. Cac cach giai phng trnh cha gia tr tuyet oi thng s dung :
* Phng phap 1 :Bien oi ve dang c ban
V du : Giai cac phng trnh sau :
1) xxxx 22 22 += 2) 0382232 22 =+++ xxxx 3) 3342 +=+ xxx
4)x
x1
32 = 5) 21
42
2=
+
+
x
x6)
2
2
110
13
2=
+
+
x
x7) 1212 22 +=+ xxxx
* Phng phap 2 : S dung phng phap chia khoang
V du : Giai cac phng trnh sau :
1) 432 =+ xx 2) 314
3+=
x
x
V. Cac cach giai bat phng trnh cha gia tr tuyet oi thng s dung :
* Phng phap 1 : Bien oi ve dang c ban
V du : Giai cac bat phng trnh sau :
1) 652 + 321
-------------------Het-----------------
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