.a 8 , +Q``2+iBQM
o2M/`2/B kk /û+2K#`2 kyRd GǶmb;2 /2b +H+mHi`B+2b MǶ2bi Tb miQ`Bbû
1t2`+B+2 ,
GǶTT`BiBQM /2b i2`K2bp+q 7Bi T2Mb2` ¨ bQKK2` 2M /B;QMH2X
G bû`B2 2bi ¨ i2`K2b TQbBiB7b /QM+ KāK2 Mim`2 [m2 H bû`B2 /2b bQKK2b 2M /B;QMH2bX SQm`n}tû-Sn=P
p+q=nap,q=Pn p=0
1 n+ 1
1
2n = 1 (n+ 1)2n
Pn
p=01 = 1 2nX S` i?ûQ`ĕK2 /2 bQKKiBQM 2M /B;QMH2- QM HQ`bP
p
P
qap,q=P
nSn=P
n
1
2n = 1
1 1/2 = 2T`
bû`B2 ;ûQKûi`B[m2 /2 `BbQM1/2X
1t2`+B+2 ,
RX aQBi">0X S` BMiû;`iBQM T` T`iB2b UH2b 7QM+iBQMb bQMiC1bm`[",1]-R1
"
arctant
t dt= [ln(t) arctan(t)]1"
R1
"
lnt 1 +t2dt.
GQ`b[m2" i2M/ p2`b y-ln(t") arctan(") ⇠"ln(") !0X .QM+ H2 +`Q+?2i ;ûMû`HBbû 2bi +QMp2`;2Mi U/2 HBKBi2 MmHH2V 2i H2b BMiû;`H2b ;ûMû`HBbû2bR1
0
arctant
t dt2iR1 0
lnt
1 +t2dtQMi KāK2 Mim`2- /QM+
+QMp2`;2Mi2b +`R1 0
arctant
t dt2bi 7mbb2K2Mi BKT`QT`2 2M y U+`arctan(t)⇠0t)X PM Q#iB2Mi #B2M H 7Q`KmH2 /2KM/û2X
kX SQm` iQmit2]0,1[- QM t22]0,1[2i /QM+ T` .a1- 1
1 +t2 =P+1
n=0( 1)n 1t2nX BMbB- lnt 1 +t2 = P+1
k=0( 1)n 1t2nlnt=P fn(t)X
G2b 7QM+iBQMbfnBMbB /û}MB2b bQMi +QMiBMm2b T` KQ`+2mt 2i H bû`B2P
fn+QMp2`;2 bBKTH2K2Mi bm`
]0,1[X 1M}M-R1
0|fn|= 1
(2n+ 1)2 [mB 2bi H2 i2`K2 ;ûMû`H /ǶmM2 bû`B2 +QMp2`;2Mi2 T` +QKT`BbQM p2+ H bû`B2 ¨ i2`K2b TQbBiB7bP 1
4n2 +QMp2`;2Mi2 T` +`Biĕ`2 /2b bû`B2b /2 _B2KMM U2>1VX 6BMH2K2Mi- T` i?ûQ`ĕK2 /ǶBMiû;`iBQM i2`K2 ¨ i2`K2 /2 "2TTQ@G2pB- QM Q#iB2Mi H 7Q`KmH2 /2@
KM/û2 ,
Z1 0
arctant t dt=
+1X
n=0
( 1)n (2n+ 1)2 jX PM T2mi `2i`Qmp2` +2 `ûbmHii 2M /K2iiMi [m2
8t2R,arctan(t) =
+1X
n=0
( 1)n 2n+ 1t2n+1. 2i 2M TTHB[mMi ¨ MQmp2m H2 i?ûQ`ĕK2 /ǶBMiû;`iBQM i2`K2 ¨ i2`K2X
S`Q#HĕK2 , miQm` /2 H 7QM+iBQM x2i Hi2`Mû2 /2 _B2KMM
AX :ûMû`HBiûb RX aQBix 2 Rc bBx > 0- HQ`b H bmBi2Å
1 nx
ã
n 1
2bi /û+`QBbbMi2 URV p2`b y UkV c /ǶT`ĕb H2 +`Biĕ`2 bTû+BH /2b bû`B2b Hi2`Mû2b- H bû`B2 P
n 1
( 1)n 1
nx +QMp2`;2 c bBx0- H bmBi2 Å
( 1)n 1 nx
ã
n 1
M2 +QMp2`;2 Tb p2`b y- /QM+ H bû`B2 P
n 1
( 1)n 1
nx /Bp2`;2 U;`QbbBĕ`2K2MiVX kX *QKK2| t|<1- H bû`B2 ;ûQKûi`B[m2P
( t)n+QMp2`;2 2i b bQKK2 pmi+1P
k=0
( t)k= 1 1 ( t) = 1
1 +tc /QM+ H bmBi2(gn)+QMp2`;2 bBKTH2K2Mi p2`b H 7QM+iBQMg:t7! 1
1 +t bm`[0,1[X
• G bmBi2(gn)+QMp2`;2 bBKTH2K2Mi p2`b H 7QM+iBQMgbm`[0,1[c
• H 7QM+iBQMg2i H2b 7QM+iBQMbgn, n2NbQMi +QMiBMm2b UT` KQ`+2mtV c
• +QM/BiBQM /2 /QKBMiBQM,8t2[0,1[, |gn(t)|= 1 ( t)n+1
1 +t = 1 ( t)n+1 1 +t 2
1 +t = (t)c H 7QM+iBQM 2bi BM/ûT2M/Mi2 /2n- +QMiBMm2 UKāK2 bm`[0,1]V 2i BMiû;`#H2 bm`[0,1[X .ǶT`ĕb H2 i?ûQ`ĕK2 /2 +QMp2`;2M+2 /QKBMû2- H bmBi2
ÇZ 1 0
gn
å
+QMp2`;2 p2`bZ1 0
gX P`-Z1
0
gn= Xn
k=0
( 1)k k+ 1 =
n+1X
k=1
( 1)k 1
k c /QM+F(1) = Z 1
0
g=h
ln(1 +t)i1 0= ln 2X jX 8n 1,8x 2, ( 1)n 1
nx 1
n2X *QKK2 H bû`B2 P
n 1
1
n2 2bi BM/ûT2M/Mi2 /2n2i +QMp2`;2Mi2- H bû`B2 P
n 1
( 1)n 1
nx +QMp2`;2 MQ`KH2K2Mi bm`[2,+1[X .QM+ bQM `2bi2Rn(x) = P
n N+1
1
nx i2M/ p2`b y 2i TQm`N bb2x ;`M/|RN|"/2X 9X S` BHH2m`b-|F(x) 1| PN
n=2
1 nx + P
n N+1
1
nxX GQ`b[m2xi2M/ p2`b+1- H bQKK2 U}MB2V PN
n=2
1 nx i2M/ p2`b y T` QTû`iBQMb bm` H2b HBKBi2b +` 1
nx !0TQm` n 2X AH 2tBbi2 /QM+A >0 i2H [m2 TQm` iQmix > A- PN
n=2
1 nx "/2
6BMH2K2Mi- TQm`x > A-|F(x) 1|"/QM+F i2M/ p2`b R HQ`b[m2xi2M/ p2`b+1X 8X GB2M p2+⇣
SQm`x >1- F(x) ⇣(x) = +1P
n=1
( 1)n 1 1 nx = +1P
k=1
2
(2k)x = 21 x+1P
k=1
1
kx = 21 x⇣(x).PM 2M
/û/mBi HǶû;HBiû ,F(x) = (1 21 x)⇣(x).
eX *QKK221 x !
x!+1 0-F(x)⇠⇣(x)m pQBbBM;2 /2+12i /QM+⇣(x) !
x!+1 1X dX .û`Bp#BHBiû /2F
X aQBix >0X G 7QM+iBQMhx:t7!lnt
tx 2bi /2 +Hbb2C1 bm`]0,+1[2ih0x(t) = tx 1(1 xlnt) t2x X .QM+h0x2bi Mû;iBp2 bm` HǶBMi2`pHH2[21/x,+1[2i TQbBiBp2 bm`]0,21/x]X .QM+hx2bi /û+`QBbbMi2 bm`[21/x,+1[2i +`QBbbMi2 bm`]0,21/x]X
PM 2M /û/mBi [m2 H bmBi2Å lnn
nx ã
n 1
2bi /û+`QBbbMi2 ¨ T`iB` /m `M;b21/xc+ 1 [mB 2bi mM 2MiB2` bmTû`B2m` Qm û;H ¨ 21/xX
e
#X fn:x7!( 1)n 12 xlnn2bi /2 +Hbb2C12ifn0(x) = ( 1)nlnn nx X aQBia >0X PM TQb2Na =b21/ac+ 1X SQm` iQmi x a- H bmBi2Å
lnn nx
ã
n Na
i2M/ p2`b y 2M /û+`QBbbMi c /QM+ H bû`B2 Hi2`Mû2 P
n Na
fn0(x) +QMp2`;2 2i- TQm`n Na- bQM `2bi2 /ǶQ`/`2n-
⇢n(x)- pû`B}2 ,
|⇢n(x)| ( 1)n+1ln(n+ 1)
(n+ 1)x ln(n+ 1) (n+ 1)a. .QM+ sup
x a|⇢n(x)| ln(n+ 1)
(n+ 1)a n!+1! 0X .QM+ H bû`B2 P
n 1
fn0 +QMp2`;2 mMB7Q`KûK2Mi bm`
[a,+1[X
• SQm` iQmin 1- H 7QM+iBQMfn2bi /2 +Hbb2C1bm`]0,+1[c
• H bû`B2 P
n 1
fn+QMp2`;2 bBKTH2K2Mi bm`]0,+1[2i b bQKK2 2biFc
• H bû`B2 P
n 1
fn0 +QMp2`;2 mMB7Q`KûK2Mi bm` iQmi b2;K2Mi BM+Hmb /Mb]0,+1[X .ǶT`ĕb H2 i?ûQ`ĕK2 /2 /û`BpiBQM i2`K2 ¨ i2`K2-F 2bi /2 +Hbb2C1bm`]0,+1[2i
8x >0, F0(x) =
+1X
n=1
( 1)nlnn nx .
AAX S`Q/mBi /2 *m+?v /2 H bû`B2 Hi2`Mû2 T` 2HH2@KāK2 3X úim/2 /2 H +QMp2`;2M+2
X GQ`b[m2x >1- H bû`B2 P
n 1
( 1)n 1
nx +QMp2`;2 #bQHmK2Mi c /ǶT`ĕb H2 i?ûQ`ĕK2 /m T`Q/mBi /2
*m+?v UQm bQKK2 2M /B;QMH2bV- H bû`B2 T`Q/mBi /2 P
n 1
( 1)n 1
nx T` 2HH2@KāK2 +QMp2`;2
#bQHmK2Mi 2i b bQKK2 pmi ,Å+1 P
n=1
( 1)n 1 nx
ã2
= (F(x))2X
#X SQm` x > 0- cn(x) = ( 1)n 2nP1
k=1
1
[k(n k)]xX *QKK2 k 7! k(n k) 2bi KtBKmK [mM/
k= n
2 2i [m2 H bQKK2 +QKTQ`i2n 1i2`K2b-|cn(x)|=nP1
k=1
1
[k(n k)]x (n 1) 1 [(n/2)2]x = (n 1)4x
n2x X SQm` 0 < x 1
2- (n 1)4x
n2x mM2 HBKBi2 bi`B+i2K2Mi TQbBiBp2 U}MB2 Qm MQMV- /QM+ H bmBi2 (cn(x))M2 +QMp2`;2 Tb p2`b yX .QM+ H bû`B2 P
n 2
cn(x)/Bp2`;2 ;`QbbBĕ`2K2MiX NX *b Qɍx= 1
X 1
[X] (n [X]) = 1 n
Å 1
[X]+ 1 n [X]
ãX .QM+
cn(1) = ( 1)n 2
n 1
X
k=1
1
k(n k) = ( 1)n 21 n
nX1 k=1
Å1 k + 1
n k
ã
= ( 1)n 21 n
n 1
X
k=1
1 k+
n 1
X
k=1
1 n k
!
= 2( 1)n 21 n
nX1 k=1
1
k = 2( 1)n 2Hn 1
n .
#X JQMQiQMB2 Hn 1
n
Hn
n+ 1 = 1 n
Å Hn 1
n
ã Hn
n+ 1=Hn
Å1 n
1 n+ 1
ã 1 n2 Å
1 +1 2
ã 1 n(n+ 1)
1
n2 = n 2 2n2(n+ 1) 0.
.QM+ H bmBi2Å Hn 1
n ã
n 2
2bi /û+`QBbbMi2X
+X S` +QKT`BbQM bû`B2bfBMiû;`H2b p2+ H 7QM+iBQMt7!1/t- QM T2mi ûi#HB` H2 `ûbmHii +HbbB[m2 , Hn⇠lnnm pQBbBM;2 /2+1X .QM+ H bmBi2ÅHn 1
n ã
n 2
+QMp2`;2 p2`b y 2M /û+`QBbbMi 2i H bû`B2 Hi2`Mû2 P
n 2
cn(1)+QMp2`;2X
AAAX *H+mH /2 H bQKK2 /ǶmM2 bû`B2 ¨ HǶB/2 /ǶmM2 ûim/2 /2⇣ m pQBbBM;2 /21 RyX .ûp2HQTT2K2Mi bvKTiQiB[m2 2M R
X PM TQb2h=x 1X *QKK2F 2bi /û`Bp#H2 2M R- m pQBbBM;2 /21- QM , F(x) =F(1) +hF0(1) +o(h) = ln 2 +hF0(1) +o(h).
PM mbbB ,1 21 x= 1 2 hln 2=hln 2 ln22
2 h2+o(h2)m pQBbBM;2 /2x= 1X
#X .ûp2HQTT2K2Mi /2⇣
⇣(x) = F(x)
1 21 x = ln 2 +hF0(1) +o(h) hln 2 ln22
2 h2+o(h2)
= 1
hln 2
ln 2 +hF0(1) +o(h) 1 ln 2
2 h+o(h)
= 1
hln 2(ln 2 +hF0(1) +o(h)) Å
1 +ln 2
2 h+o(h) ã
= 1
hln 2 Ç
ln 2 +h Ç
F0(1) +ln22 2
å +o(h)
å
= 1
h+ ÅF0(1)
ln 2 +ln 2 2
ã +o(1) RRX .ûp2HQTT2K2Mi bvKTiQiB[m2 2M R U#BbV
X SQm`n 12ix2[1,2]-t7! 1
tx 2bi /û+`QBbbMi2 bm`[n, n+ 1]U[mB 2bi mM BMi2`pHH2 /2 HQM;m2m`
RV- /QM+1. 1 (n+ 1)x
Z n+1 n
/t tx 1. 1
nxX PM 2M /û/mBi [m2 ,0vn(x) 1 nx
1 (n+ 1)x.
#X SQm` x 2 [1,2]- H bmBi2 Å 1 nx
ã
n 1
+QMp2`;2 Up2`b yV c +QKK2 Pn
k=1
Å 1 kx
1 (k+ 1)x
ã
= 1 1
(n+ 1)x- H bû`B2 P
n 1
Å 1 nx
1 (n+ 1)x
ã+QMp2`;2X .2 HǶ2M+/`2K2Mi /m UV- QM /û/mBi H +QMp2`@
;2M+2 /2 H bû`B2 P
n 1
vn(x)X +X SQm`x2]1,2]- Pn
k=1
vk(x) = Pn
k=1
1 kx
Z n+1 1
/t
tx n!+1!⇣(x) Z +1
1
/t
tx =⇣(x) 1 x 1X /X G bû`B2 P
n 1
vn +QMp2`;2 bBKTH2K2Mi bm`[1,2]X PM MQi2 Rn(x) = +1P
k=n+1
vk(x)H2 `2bi2 /ǶQ`/`2 n/2 H bû`B2X .ǶT`ĕb UV-0Rn(x) +1P
k=n+1
Å 1 kx
1 (k+ 1)x
ã
= 1
(n+ 1)x limk!+1 1 kx = 1
(n+ 1)xX .QM+ sup
x2[1,2]|Rn(x)| 1
(n+ 1)1 n!+1!0X .QM+ H bû`B2 P
n 1
vn +QMp2`;2 mMB7Q`Kû@
K2Mi bm`[1,2]X
3
2X SQm`x2]1,2]-vn(x) = 1 nx
1 1 x
Å 1 nx 1
1 (n+ 1)x 1
ãcvn(1) = 1
n ln(n+ 1) + lnnX vn 2bi +QMiBMm2- bm7 T2mi@āi`2 2M RX
1M R , 2M TQbMih=x 1- 1 nx = 1
n+o(1)T` +QMiBMmBiû /2 HǶ2tTQM2MiB2HH2x7!n x 2M R 2i 1
1 x Å 1
nx 1
1 (n+ 1)x 1
ã
= 1
h 2 hlnn 2 hln(n+1) = 1 h
⇣(1 hlnn+o(h)) (1 hln(n+
1) +o(h)⌘
= ln(n+ 1) lnn+o(1)c /QM+ vn(x) = 1
n+ ln(n+ 1) lnn+o(1)X .QM+vn2bi +QMiBMm2 2M RX
PM 2M /û/mBi [m2 H bû`B2 P
n 1
vn2bi mM2 bû`B2 /2 7QM+iBQMb +QMiBMm2b bm`[1,2]X G +QMp2`;2M+2 mMB7Q`K2 bm`[1,2]2Mi`ŗM2 /QM+ H +QMiBMmBiû /2 b bQKK2 bm`[1,2]X
PM 2M /û/mBi [m2⇣(x) 1
x 1 =+1P
n=1
vn(x) = Å+1
P
n=1
vn(1) ã
+o(1) = +o(1)m pQBbBM;2 /2 1+X .ǶQɍ⇣(x) = 1
x 1+ +o(1)m pQBbBM;2 /21+X RkX TTHB+iBQM
S` mMB+Biû /m /ûp2HQTT2K2Mi HBKBiû 2M1+Uûp2Mim2HH2K2Mi 2M KmHiBTHBMi T`(x 1)V- QM /û/mBi /2 3XU#V 2i NXU2V H2b û;HBiûba= 12i F0(1)
ln 2 +ln 2
2 =b= X .ǶQɍF0(1) = ln 2
Å ln 2 2
ãX
.ǶT`ĕbAX9XU#V-+1P
n=1
( 1)n 1lnn
n = F0(1) = ln 2 Åln 2
2 ãX
AoX *H+mH /2 ⇣(4)2i TTHB+iBQM ¨ H T?vbB[m2 , SQm`x >1- QM TQb2⇣(x) =X
n 1
1
nxX PM `TT2HH2 U2i QM /K2iV [m2⇣(2) =X
n 1
1 n2 =⇡2
6 . SQm`m2N⇤2in2N⇤- QM TQb2 , (m, n) = 2
mn3+ 1 m2n2+ 2
m3nX
RjX X aQBi X
m 1
X
n 1
(m, n) X
m 1
X
n 1
(m, n+m) X
m 1
X
n 1
(m+n, n).
.ǶmM2 T`i- QM T2mi pû`B}2` [m2 (m, n) (m, n+m) (m+n, n) = 2 m2n2X HQ`b
X
m 1
X
n 1
(m, n) X
m 1
X
n 1
(m, n+m) X
m 1
X
n 1
(m+n, n) = X
m 1,n 1
2 m2n2
= X
m 1
ÑX
n 1
2 m2n2
é
=X
m 1
2 m2
ÑX
n 1
1 n2
é
= 2 ÑX
n 1
1 n2
é ÑX
m 1
1 m2
é
= 2⇣(2)2. S` BHH2m`b ,
G T`2KBĕ`2 bû`B2 +Q``2bTQM/ ¨ H bQKK2 /2 iQmb H2b i2`K2b (a, b)TQm`(a, b)2(N⇤)2UTHM bmTû`B2m` /`QBiVX
G b2+QM/2 bû`B2 +Q``2bTQM/ ¨ H bQKK2 /2b i2`K2b (a, b)i2Hb [m2(a < b)bBimûb bi`B+i2K2Mi m /2bbmb /2 H /B;QMH2 /m [m`i /2 THMX
G i`QBbBĕK2 bû`B2 +Q``2bTQM/ ¨ H bQKK2 /2b i2`K2b (a, b)i2Hb [m2(a > b)bBimûb bi`B+i2K2Mi 2M /2bbQmb /2 H /B;QMH2 /m [m`i /2 THMX
6BMH2K2Mi- HǶ2Mb2K#H2 +Q``2bTQM/ ¨ H bQKK2 /2b i2`K2b (a, b)i2Hb [m2a=bUH /B;QMH2 /m THMV- +Ƕ2bi ¨ /B`2P
a2N (a, a) =P
n 1
5
a4 = 5·⇣(4)X
#X .QM+5⇣(4) = 2⇣(2)2= 2⇡4
36 2i QM T2mi HQ`b 2M /û/mB`2 [m2
⇣(4) =X
n 1
1 n4 =⇡4
90.
R9X .ûi2`KBM2`- T`ĕb pQB` DmbiB}û bQM 2tBbi2M+2- 2i 2M /ûiBHHMi H2b +H+mHb HǶBMiû;`H2Z +1 0
t3 2t 1dt SQm`t >0- +QKK20exp( t)<1- QM t3
et 1=t3e t 1
1 e t =t3P
n2Ne (n+1)t=P fn(t)X
*?[m2fn2bi +QMiBMm2 bm`]0,+1[- TQbBiBp2b 2i BMiû;`#H2 +` 7mbb2K2Mi BKT`QT`2 2M y 2io(1/t2) 2M+1X G bû`B2 /2 7QM+iBQM +QMp2`;2 bBKTH2K2Mi p2`bf [mB 2bi +QMiBMm2 2i BMiû;`#H2X
SQm`n2N-Z
|fn|= 1 (n+ 1)4
Z +1 0
u3exp( u) du2M TQbMiu= (n+1)t+?M;2K2Mi /2 p`B#H2b
#BD2+iB7X
S` ASS Qm 2M `2+QMMBbbMi H 7QM+iBQM - QM }MH2K2Mi Z
|fn| = 6
(n+ 1)4 [mB 2bi H2 i2`K2
;ûMû`H /ǶmM bû`B2 +QMp2`;2Mi2 T` +`Biĕ`2 /2 _B2KMMX .QM+ T` BMiû;`iBQM i2`K2 ¨ i2`K2 /2 "2TTQ@G2pB-Z
f=X
n 0
6
(n+ 1)4= 6⇣(4) = ⇡4 15X R8X aQBiM = c
4 Z +1
0
8⇡hc
5
1
exp(kBhcT) 1d X PM TQb2t='( ) = hc
kB T +?M;2K2Mi /2 p`B#H2b #BD2+iB7X HQ`b = hc
kBtT 2id = hc kBt2T dt 1iM =
Z 0 +1
2⇡hc2kB5t5T5 h5c5
( hc) kBt2T
1
exp(t) 1dt= Z +1
0
2⇡hc2kB5t5T5 h5c5
hc kBt2T
1 exp(t) 1dt T`ĕb bBKTHB}+iBQMb 2i /ǶT`ĕb HǶBMiû;`H2 +H+mHû2 H [m2biBQM T`û+û/2Mi2-
...= 2⇡kB4T4 h3c2
⇡4 15= T4 p2+ = 2⇡5k4B
15h3c2X
Ry