1. Ряды (853737), страница 10
Текст из файла (страница 10)
&:nn+1jfn(x)j = jpxjn C jfn+1(x)j = pjxnj + 1 Cn+1pnn jxjpnjfjxjjxjn+1 (x)jnlim!1 jfn(x)j = nlim!1 pn + 1jxjn = nlim!1 jxjnpn + 1 =vus nu1 = jxj:uu=jxjlim= jxj nlimn!1 u!1 n + 1t1 + 1n! , , jxj < 1, , jxj > 1. 8., R = 1 (;1 1):& . . x = 1 1 1Xpn :n=1% (. U2) . x = ;1 1X(;1)n p1n :n=1% . ! N.; , . + G;1 1).
x = ;1 . >-, $ !!#$#+6 5$6 .1 ( ; 2)nX1)2n 41 ( + 1)5 2nX2)2 +1 4n=0xn=1nnxn1471 (;1)n;1 ( ; 5)nX43nn=11 ( + 3)2nX5)2 25n 4n=11n+1nX7) (;1)n+1 2 (q ; 4) 4( + 1) ln( + 1)n=13)1 ( + 5)2n;1X2 4n 4n=11 ( + 1)nXp46)n 2 +1n=1 21 + 1 n nX8)4)xnxnn=1n@0 4) = 0 "4(;1 1)4(2 8] = 8 "4@;7 ;3) = ;7 "4@;8 2]4@;3 1]47 97) 2 2 = 29 "48) (;1 1)xxxnnx1)2)3)4)5)6)nxnnxx:|||||148nx : 7/@0/ <</=0/-//1 1X. R { an xn: ; n=0 x 2 (;R R) :Zx1 an xn+1XCS (t)dt =n+1n=001X0S (x) = n an xn;1n=11X S (x) = an xn:n=0 6.7 ( ), { 6.8 ( "" ) (.
U6).- , (. 6.8), , , +, 0 + . .% + . . c , + . 7.1. @ . :1 nXxC(7:1)n=01 xnXn:< /# :1 nXx = 1 + x + x2 + x3 + : : : + xn + : : : Cn=1n=01 xnXn=123nxxxn = x + 2 + 3 + :::+ n + ::: :149(7:2)/, "" . /, 0 +. (7.1) x. ! , jxj < 1, , jxj > 1: 8., 0 R = 1 + 0 (;1 1):, . + 0 . jxj = 1 (7.1) , 0 , .
# . 8., . (7.1) 1(;1 1):X x = 1 (7.2) n1 : % n=1. !, , .1 (;1)nX: x = ;1 (7.2) n=1 n! N. ; , . (7.2) + G;1 1). x = ;1 0 . > 7.2. @ . 2n1X(x;2)n(7:3)(;1) n 4nn=1 , "".< & (. 6.8), , "", .@ . 8 0 . , , F. &:2(n+1)2njfn(x)j = (x n;42)n C jfn+1(x)j = ((xn ;+ 2)1) 4n+1 C2n+2 n 4njf(x;2)n+1 (x)jnlim!1 jfn(x)j = nlim!1 (n + 1) 4n+1(x ; 2)2n =1502n (x ; 2)2 n 4n1 (x ; 2)2 lim n =(x;2)== nlimn2nn!1 n + 1!1 (n + 1)4 4 (x ; 2)4221(x;2)(x;2)= 4 nlim!1 1 = 4 :1+ n! , , (x ; 2)2 < 1 ., jx ; 2j < 2 , jx ; 2j > 2:4% , R = 2, (2 ; 2 2 + 2) = (0 4):& .1X x 2 f0 4g (;1)n n1 n=1 N.
8., . G0 4]. x 2 f0 4g .@ . . 2n;111 0 n (x ; 2)2n 10 XXA = (;1)n 2n(x ; 2)@(;1)=n 4nn 4nn=1n=12n;11X2(x;2)n:= (;1)4nn=1; 0 (7.3) "", . !. . .2n;11X2(x;2)n x = 0 ( x = 4) (;1) n4n=111XXn+1(;1) ( (;1)n ), , n=1n=10 , . # .2n;11X2(x;2)n; , . (;1)4nn=1 (0 4): >151 7.3. @ 1 xnXn=1 n .< , 7.1 , 0 R = 1 (;1 1): ! S (x) .. x 2 (;1 1) :1 nXS (x) = xn :n=1! "" :1 xn !0X0S (x) = x 2 (;1 1):n=1 n + . 1XS 0 (x) = xn;1n=1, + , S 0 (x) = 1 + x + x2 + : : : + xn + : : : : . 0 q = x: ; jxj < 1 1 + x + x2 + : : : + xn + : : : = 1 ;1 x :8., S 0(x) = 1 ;1 x x 2 (;1 1):! , S (0) = 0, ZxZx 10S (t)dt = 1 ; t dtC00Zx 1', S (x) = 1 ; t dt x 2 (;1 1):0Zx0dt = ; Zx d(1 ; t) = ; ln j1 ; xj1;t1;t0152S (x) = ; ln j1 ; xj x 2 (;1 1): > 7.4.
@ 1X(;1)n+1 (2n + 1)x2nn=1 0 .< ! 1 S (x). ; X (;1)n+1 x2n+1 n=1"", . @ 1X(;1)n+1 x2n+1 = x3 ; x5 + x7 ; x9 + : : : + (;1)n+1 x2n+1 + : : : :n=1% q = ;x2: ! , x2 < 1 . jxj < 1 , jxj > 1: % , , 0 R = 1, (;1 1):1X! (;1)n+1 x2n+1 S1(x) n=1.
x 2 (;1 1) 1XS1(x) = (;1)n+1 x2n+1 = x3 ; x5 + x7 ; x9 + : : : + (;1)n+1x2n+1 + : : : :n=1; jxj < 1, 3xx ;x +x ;x1 + x2 :8., x (;1 1) 3xS1(x) = 1 + x2 :! "" a 1533579+ : : : + (;1)n+1 x2n+1 + : : : =1x3 A0 C1 + x21XS10 (x) = (;1)n+1 (2n + 1)x2n = S (x) x 2 (;1 1):n=1; , , . 0 3 10S (x) = @ 1 +x x2 A x 2 (;1 1):',0 3 10223222@ x A = 3x (1 + x ) ; 2x x = x (3 + 3x ; 2x ) =1 + x2(1 + x2)2(1 + x2)20S10 (x) = @22x(3+x= (1 + x2)2) S (x) = x(1(3++x2x)2) x 2 (;1 1): >22 7.5. +. " x12 (x + 1):< ; 1 = ; 1 !0 x 2 IR n f0gCx2x1; x1 = ; (x + 11) ; 1 = 1 ; (x1 + 1) = X (x + 1)n(7:4)n=0 x jx + 1j < 1 . x 2 (;2 0)C 1 !0 X1(7:5); x = n(x + 1)n;1 x 2 (;2 0)n=1 :11 =Xn;1 x 2 (;2 0):n(x+1)2xn=1 (7.4) " , (7.5) { "" . >154-, $ !!#$#+6 5$1.
6 , " " %%<.1 n11 ( ; 5)nnXXXn)4) (;1) ( + 1)! 4)n+12 n+1n=1 3n=1n=1 ( + 1) 22. 6 "" :11 ( + 1)( + 2) nXX4) (;1)n ( + 1)( + 2) n 4)2n=0n=01 ( ; 3)nX)+1n=03. 7 %"<0 1 :xxnxnnnxn:nnxnx:n2x) ( ; 1)) ( + 3)4xx:1. ) @;3 3) (;3 3)4) (;1 +1) (;1 +1)4) @3 7] @3 7)) (1 ;1 )3 2 (;1 1)42. ) (1 +2 )3 2 (;1 1)4) ; ln(4;;3 ) 2 (2 3) (3 4)4 0 = 31X3. ) 3n;1 ( + 3)n;1 2 (;6 0)4n=11X) (;1)n ( ; 1)n;1 2 (0 2)x xxxnn=1xn xxx x x:|||||155 xx:: 8 ?0 @ -I/* . -(.
f (x) { "" x0 ". < ! " f (x) x0 { 0 0001 f (n)(x0 )Xn = f (x ) + f (x0 ) (x ; x ) + f (x0 ) (x ; x )2 + : : :(x;x)00001!2!n=0 n! x ; x0. E x x0 1 (n)Xf (x) = f n(!x0) (x ; x0)nn=0 " f (x) + ; x0 ( x ; x0). x0 = 0 ; 0 (0)00 (0) 2(n) (0)ffff (0) + 1! x + 2! x + : : : + n! xn + : : : + 5.8 . , "" x0 " ;. ( " f (x) = e;1=x , # f (0) = 0. ..
, + ., 0 " , . . $ "f (x) 6 0 { .) /, ; " , + + (P. +), ; "" x0 " , . . . x = x0., 0 " x0 ;. . + x, + .231 xnXxxxe == 1 + x + 2! + 3! + : : : x 2 IRCn=0 n!1562sin x =cos x =1 =1;x(1 + x) ==1 (;1)n;1 x2n;1X35xx= x ; 3! + 5! ; : : : x 2 IRCn=1 (2n ; 1)!241 (;1)n x2nXxx= 1 ; 2! + 4! ; : : : x 2 IRCn=0 (2n)!1 nXx = 1 + x + x2 + x3 + : : : jxj < 1Cn=01X1 + ( ; 1)( ; 2)n!: : : ( ; n + 1) xn =n=11 + x + (2!; 1) x2 + : : : jxj < 1 { . ( , #. )C231 (;1)n;1xnXxxln(1 + x) == x ; 2 + 3 ; : : : ; 1 < x 1Cnn=1351 (;1)n;1x2n;1Xxxarctg x =2n ; 1 = x ; 3 + 5 ; : : : jxj 1:n=1&.
+, + + .+ ; x ; x0 "( ). 8.1. +. " ; x . . :1) e3xC2) cos 5xC3) sin x2C4) p 1 3 :27 + x< 1) y = 3x . + ey :1 3nxn1 yn XX3xy:e = e = n! =n=0 n!n=0. + " ey y, + " x.2) y = 5x . + cos y:1 (;1)n y2n X1 (;1)n 52nx2nXcos 5x = cos y ==(2n)! :n=0 (2n)!n=01573. + " cos y y, + " x.3) y = x2 . + sin y:1 (;1)n;1 y2n;1 X1 (;1)n;1 x4n;2X2sin x = sin y ==:n=1 (2n ; 1)!n=1 (2n ; 1)!.
+ " sin y y, + " x.3x113;1=34) . p= (27 + x ) = 3 (1 + 27 );1=3, , 327 + xy = (x=3)3 . . +, p 1 3 = 31 (1 + y);1=3 =27 + x 1 ! 1!11 ;3 ;3 ; 1 : : : ;3 ; n + 1 nX11=3+3y =n!n=11Xn ; 2) yn =1= 3 + (;1)n 1 4 73:n:+1: (3n!n=11X= 31 + (;1)n 1 4 734:n:+1: (3n!n ; 2) x3n:n=1. + " (1 + y);1=3 ;1 < y 1, + " ;3 < x 3. >33+ " . +, + . + + . (x ; x0).
8.2. +. " ; x:1) (x2 ; 1)exC2) ln(1 ; 5x + 4x2):< 1) &. + ex, 1 n X1 xn X1 xn+2 X1 xn2x2 xx2 X x(x ; 1)e = x e ; e = x;=; n! =n=0 n! n=0 n! n=0 n!n=01581X1 xn+2Xn+2x; 1 ; x ; (n + 2)! ==n=0n=0 n!101X@11A xn+2:= ;1 ; x +;n=0 n! (n + 2)!F + x.2) + + . ":ln(1 ; 5x + 4x2) = ln(1 ; 4x)(1 ; x) = ln(1 ; 4x) + ln(1 ; x)( x < 1=4). ;., . + ln(1 + y)( y = ;4x " y = ;x { ), 1 (;1)n;1 (;4x)n X1 (;1)n;1 (;x)nX2ln(1 ; 5x + 4x ) =+=nnn=1n=11 4nxn X1 xn X1 ;4n ; 1 nX= ;n ; n=n x:n=1n=1n=1F + ;1=4 x < 1=4. > 8.3. +.
" f (x) = ex ; x0 = 1, . . x ; 1.< 8 + ( ;). F 0 " f (x) x = 1. .f (n) (x) = ex n = 0 1 2 : : :, f (n) (1) = e 1 eXxe = n! (x ; 1)n:n=0@ + x, + . #.+ y = x ; 1. ;1 e1 yn XXx1+yye = e = e e = e n! = n! (x ; 1)n:n=0n=0. + " ey y, + x. >159 8.4. +. " f (x) = ln x ; x0 = 2, . . x ; 2.< .!!x;2x;2f (x) = ln(2 + (x ; 2)) = ln 2 1 + 2 = ln 2 + ln 1 + 2 , y = (x;2)=2 .
+ ln(1+y),1 (;1)n;1 ynX=ln x = ln 2 + ln(1 + y) = ln 2 +nn=11 (;1)n;1 (x ; 2)nX= ln 2 +:n2nn=1+ " ln(1 + y) ;1 < y 1,., + 0 < x 4. > 8.5. +. " f (x) = px ; x0 = 2, . . x ; 2.< .qp x ; 2 !1=2f (x) = 2 + (x ; 2) = 2 1 + 2, y = x ;2 2 . . +, 1 12 ( 12 ; 1) : : : ( 21 ; n + 1) npx = p2(1 + y)1=2 = p2 + p2 Xy =n!n=11pp p2 X= 2 + 2 y + (;1)n;1 2 1 3 5 2: n: :n(2! n ; 3) yn =pn=21pX= 2 + 42 (x ; 2) + (;1)n;1 2 1 3 5 4: n: :n(2! n ; 3) (x ; 2)n:n=2+ " (1 + y)1=2 jyj 1, ., + 0 x 2.
> 8.6. +. " f (x) = 5 +1 2x ; x0 = 3, . . x ; 3.160p<.f (x) = 11 + 2(1x ; 3) =1102(x;3)A11 @1 +11, y = ;2(x ; 3)=11 . + 1=(1 ; y), 1 n X1 (;1)n 2n1 =1 = 1 Xn:y=(x;3)n+15 + 2x 11(1 ; y) 11 n=0n=0 11+ " 1 ;1 y jyj < 1, ., + jx ; 3j < 112 , . . ; 52 < x < 172 .
>-, $ !!#$#+6 5$7 %"<0 F " 0 (. . ; 0). E ".1) p1 x 0 = 042) 1 ;23 2 0 = 04xxexx3) 3arctgx5) sin27) sinxxxx0 = 044) sh0 = 046) pxx0 = 348)x9) ln(5 + 3)x0 = 04xx9+xxxp3x10) 4 +1 30 = 14xx0 = 042x0 = 14x0 = ;2:x1)1 (;1)n nX,n !n=0 2xnx2 IR42)1611Xn=02 3n2n ,xpj j 1 34x <=1 (;1)n;1 2n+21 2n;1XX,jj144),2 IR42 ;1n=1n=1 (2 ; 1)!1 (;1)n;1 22n;1 2nX,2 IR45)(2 )!n=11nX6) 3 + (;1) 12n332n+1(2! ; 1) 2n+1, j j 34n=11X2 IR47) sin(3 + (! ) 2) ( ; 3)n ,n=01 (;1)n;12 5 (3 ; 4)X;1n8) 1 + 3 +(;1), 0 24n3 !n=21n;1 nX9) ln 8 + (;1)8n 5 ( ; 1)n, ; 35 135 4n=11 nX; 43 .10) 2;n3+1 ( + 2)n , ; 83n=03)xxxnxnxx:::nxnn =nxxxx:::nxnnxnxx< xx< x <||||| & $ $.