-=.T
Bai
2
Bai
1
vdi
(S)
ld
phia
ngoei
crla mit
cEu
tdm
0 bdn kinh
R.
qr+
74
*
<
*
Bei
3
vrTq
^
Khai
tridn
thinh
chu6i
nEuy6n
2
him
sd tn(I
+
x)vit
In(I
-x).
Trinh
biy c6ch
tfnh
gEn
dring
gi5
tri
cia In7.
.
rnUorvc
pAr
Hoc
sU
pHAu
rp HO
cHi MrNH
v. e a
'
,,
'
.
xn-oh
vhil}';"i6p'rV$i;
r
dd]
''r
-
Hmffil'
)b+1
6*%
:
IA
",
:s
,;i
Tinh
tich
ph6n
durdnn
0,u
Gy
+
2x-y)
dx +
(xy-x
+
2y)
dy
",,'
.Fi*-
li
v6i
(L)
li
dudngtrdn
rd
+
f
-2ay=
O(a>0)theo
2c5ch:
a) Tinh
trfc ti6p
b) Dirng
c6ng
thitc
Green.
S0\
\
\
>*-
ff
Tinh
tich
ph6n
mit
JJ
o,
1l
ayaz +
f
axdz +
zJ
axayl
l
fada+?nsaTiii&ngu6
cG
pLild
trinh
vi
ph6n:
4xf
-(x)
+xf
'(x)+f(x)=e
.
Bii s
Cho
him
s6 f(x)
=
2x
vdi x .
(41).
HEy
bidu di6n
f(x)
thinh
:
a) chuSi
Fourier
2
n,
sin
ntxvdi
An ri
c6c
h6
s6 Fourier.
n=l
+@
f
b) Tich
phan
Fourier
J
o
A(a)
cLrsdx
da vdi
A(a)
ld
bi6n
ddi Fourier.
frH
i\
1/
I
I
r
i.
i-j
L{
ri
I
\
'\i
\ i \
a '{
'i.
''i