!"#$""#$%
&'!()
*+,$
!"#$ %##&$'&()%*+,-
.+&"/0"12 &()%3
4566#&789:+7-:-./-$*-
0;<*$ !="02$'$>?@3;A#&+B
C+B#D0E;F1;G>3
*+,"% $ &!:H++B9IJ
% 08
K$>H*!?(LM-*"(*$>!+-*0N+B0
OPD0,*#QL-*!?(KL*-+R"R S0
13TO
UM =
3
0V+(W!+"R 3X+$"#D0$>?Y.+"Z3
[W!+"R 3[$>"(+BV$
M
M
\
=
1
.+"("R 31&!0W0$ R 3
*+,%]&70O*#H6^
-^
+R+7"60_M3
`>PV+R$,$"6#P$ O*#^
*%ab3c
!de&S0O*#^
$ O*#^
*%bb3f+R
O*#H^$ "*%W00O*#^
$ ^
+7"61>O
,0$"#K$ fD0O*#^H0#O08
g[O*#^eK1%/0&*0+=$ ^
KL4h3
g[O*#^ef1%/0&,+;,+*+=$J$"#D0$>
PV"O*#^
3Vf? 9O3#)D0O*#$ +^
f3
*+,-
K$>)&+7Z090++'F0d;A,;A"18
π
=
$
4b-
ϕπ
+=
3iA"190+=(;+(
? 8
b-
ϕπ
+=
3V
ϕϕ
<
$ P
+"?O3X+P
0C-
j
$ j3
K?.?FC"<k+213`>,*!?(L*-?FCl
,+2*LMMfU3mRVS0+n$>+B?FC,'9 )3]
VB+C!09+'*$>!+$0!0LU
3TO
UM =
3
0#Z0N*V.+B++*$>"ZV3
o0*"ZV1$>90++'F03`;A"190+D0$>3
]J"6J0+k+2-'9AC!-!J0+$"#:SD0$>
-!Z0? ?Y$>+/0$"#?FC_$'$"#:S3
X+Z+B$>+/0$"#,+EO;4?E?2M43
pppppppppppppppqrpppppppppppppppp
Q
^
q1
P
V
V
*
q1
"#$""#$%
&'!()
*+,./ 0102 /3
*+,$
h+B
$4*0 567 ,8259:;<2=>?/0;02@
pT(,06*2$ *sE3
p]0 J W+A$*2A+!+?>;3
pq++J>;D0J#(;$&..N+A
$*2-Y@6D0N+*B%+1!-D
! -"0 $' 3
p1W12J>;;d(;$t+A$*21:-
+,-? #&3333
pq++t"eD0$A2$t+D0J
-9)*1!;,BC"03
p5)*Z0t+3
pX++'*&J8+79d#&-t
"e333
"4ABC>D2?/E!
+ Hin tưng t cm khi đng mch.
!"#
!$%&'
m,[1+um
?0F+u
m
?NNR9d+&"ee
0!03
!()*
[+,[9F+&"%0
ENM+v3f"
9F+&E? N/0!9:0+=
⇒
"!9:CO&9F+&%23<+?>T<pCA9F+&
%2,96!?:"0,9F+&"
*E?0,3`1$>m
?NN3
+ Hin tưng t cm khi ngt mch.
!+"#
!$%&'
[.[,+um*.0
?,<"70+,.3
!()*
[.[9F+&"
Nv+M? N/0!9:0+=
⇒
"!9:CO&9F+&%23
<+?:T<pCA9F+&%2d'$9F+&"9
7:"0-9F+& +/0+um3KR*"Z0.[1Z
0C"0)N"OHZ+9F+&%2"0"O
?9+,? +um?,<?"7.3
%4;>3>D FG 21H2?I
wT8TO(9:+7,'9 ?
S'9 D0E;F3
pK.A9:+7$ +&1$x
pN#&0C++(v$ yD09:3
pm&"eD0+9:8
,
-
. =
3
pKR*0,8
,
-+
/
,
-
+
/
.
ρ
ρ
=⇒==
p5d:C+*!?(D0+9:? 8
0/
++0/ =⇒=
Q
m
T-Q
[ z-"
"
m
[
m
z-"
T-Q
V
A
pN$ 0,8
0,
-
/
ρ
=
p5d%"0$>?@"0+(+&"eO{$ *!?("5D0+7N+,
1+('9 D0E;F? ?
wT8TO(9:+7,'9 ?
S'"D0E;F$ ?
?01+(?
3
wT48TO(9:+7,'9 ?
4
S'0D0E;F$ ?
?01+(?
4
3
p`>B#D0E;F+(C+8`L?
3?
3?
4
*+,"
b+B
G4J02 K,B6L ?/M NB92>OP2Q>:R2I
p]J!ER 3
piA"1B+D0$>
"R8
12
=+
p|%G]$>.+"Z3
p]?]^0,8
.
3
12
4
=−
α
⇒
.
3
1
4
−=
α
p`>"Z*fLM
⇔
M
=−
.
3
4
α
⇒
α
.3
4
=
4
p};96+?>% AE-0,8
]P
~~ =
⇔
α
.3.
4
+=
⇒
α
−= .3
4
a
N4$ a
⇒
4
=
α
b
p`>$>"Z+0
]
$R ? 8
4
h_-M
4
≈==
α
h
54ST2??/M502 K, NB92>OP2Q>:R2I
p]J!ER 3
pX•$>$"#|"PV
*0"(" $
β
=(
\
3
piA"1B+D0$>
"R8
12
=+
p]?|^0,8
.
3
12
(
=−
β
⇒
.
3
1
(
−=
β
_
pKR*;96+?>% AE-0,8
|P
~~ =
⇔
β
.3.
(
+=
⇒
β
−= .3
(
€
pN_$ €0,8
4 −=
β
1
•
piA"1+?)JD0K*+28
M
=+++ 1562
p];A"1?&C^8
+=+=
==
ββ
ββ
17176
115
M
p[.+"(18
M
M==
θβ
$ ‚
Lƒ„
pNM$ 0,8
θθµ
117 =+
Mb-M
4
4
≈
−+
−
=
+
=⇒
θθ
θθ
θ
θ
µ
7
17
1
UE>N2? +,./B92672?!
α
P
]
^
2
1
Q
^
θ
2
P
V
6
1
1
2
C
5
*+,%
a+B
V0 B92>/P, W FG 0 >X,YD2I
poA+7%8
w[0,[^8
U
U
8888
→→
w[,[^8
U
44
UU
44
U
U
888 888
→→→
gq8[^eK3
p5%!d*+=[^*,963
M
UU
U
==⇒≡≡⇒ 88
3
p0,8
4h
U
U
878788 =−=⇒==+
M
U
U
88
88
9 =
+
=⇒
3
p0,8
4a4a
44
U
888 =⇒==+
4M
U
44
U
44
88
88
9 =
+
=⇒
gq8[^ef3
pmB+;,+%/0&*+=OO;$"#D0PV10&
$"6#0?,"0*H&$"6#3
p0&$"6#$>PVe$d3
M
U
988 ==⇒∞=⇒
3
M
U
U
U
1 8 8888 ==−=−=−=⇒=+
p0?,"0*H&$"6#3
4M
4
U
4
988 ==⇒∞=⇒
3
8 8 88 −=−−=−−=⇒−==+ aM4M_M
4
U
U
4
pX•[^0,8
wMM€MMhM
aM
M
U
9
8
89
=++−⇒
−
+
−
=+=
99 MMMM€MM•MM
U
−=+−=∆
3
p5f? 9Ow,&
bMMMMM
U
99 =⇒=−⇒=∆⇒
p`>8CL^
fL4M
*+,-
h+B
$4V0 B92
$ZG[4\
]
"
^R]
pN+7$•pA0,8
3
ϕπ
α
ϕπα
−
=⇒
−
=
p58P$
ϕπ
−
*+=
+BP
0C
*…L
π
α
=⇒
3
pTY+,0,8
b
0C
=+=
p`>8
h
b
h
0C
π
ϕ
π
ϕπϕπ
=⇒=−⇒==−
pi00+D090+=(;8jLj
†…L‡U4
"4JR/>;02 ;2_` _H[;I
G4a>b/?/G2>c_d ,e32B=2?Bf2_d ^g>Ob/?/0JI
piA"1+?)JD0$>8
9
igfg‚ L0
r r r
r
3
p]?^C8pfp*
/∆
L0
⇒
fL†0p*
/∆
p[$>"Z1fLM
M€-M
/ =
−
=⇒=
−
=∆⇒
54/f>16A2?>Oa2hG;B=2?I
piA"190+8
ϕϖ
+=
*
2
1
5
8
V
^
C
j
j
…
^
C
p!,8
UM :8
==
ϖ
p[$>e`]V8
⇒=∆−⇒=+ MM
MM
/52
/ M-M
M
===∆
3
p„+Z$>++(+*"ZV? 8
0
oL LM-M€
L€3
pT+D0$>*"ZV? 8CL€pMLp3
p`>!D0$>*"ZV? 8$L0L
aM
U3
pV+90+D0$>8
3
h
=+=
ϖ
3
p[LM
4
M
U
M
4M_
M
MM
π
ϕ
ϕ
ϕ
−=⇒
<
−=
⇒
>
−=−=∆−∆=
⇒
3
//
3
piA"190+8
4
Mh
π
−=
3
4b/B/3^g>i,G^9>OD jk
B
l%k
>
_K2"#$%!
p[
4
a4
;;;;
±=±=⇒
=⇒=
p[LM
>
−=
⇒
M
4
M
M
3
⇒
ˆ$+BK
M
"$F"F3
p[$>/0$"#,~
+
L4~
?+2$+BK
"$F"F3
p|,/•2$Z+B$>/0$"#
,~
+
L4~
?2M4? 8
παϕϕ
+−=∆
p`
bM4
a
M4
‰
4
=
−
==⇒==
π
αα
p`>8
4M
4M•
4
4M•
3bM4
44
π
ϖ
ϕπ
π
ππ
ϕ
=
∆
=⇒=+−=∆
Ch : 4<=>?)@<<3ABC
P
pP
K
K
M
LK
a
pPU PU
K
4
Š
K