МАТЕМАТИЧЕСКИЙ АНАЛИЗ

62
Соколова О.А. КРАТКИЙ КУРС ЛЕКЦИЙ ПО ДИСЦИПЛИНЕ «МАТЕМАТИЧЕСКИЙ АНАЛИЗ» для студентов специальности «Вычислительные машины, системы и сети»

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КРАТКИЙ КУРС ЛЕКЦИЙ ПО ДИСЦИПЛИНЕ«МАТЕМАТИЧЕСКИЙ АНАЛИЗ»для студентов специальности «Вычислительные машины, системы и сети»

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  • ..

    ,

  • I

    1. . . . . .

    X Y

    f

    XxYy . ,

    y x ( ).xfy = x U U ( UU), y U U, X - U U() , Y U U () . xOy, ( ),xfy = UU .

    . :

    ( ),xyy = ( ),xFy = ( ).xgy = U

    , ,

    , () . : UU, UU UU.

    U U U : y=const, (x - ),

    ),10(

  • .,,arccos,arcsin arcctgxarctgxxx

    , , (), U .

    U U: ( ) ( )( ) ( ) ( ) .3,sinlog,1 23 xx arctgxfexxfxxxf === U,U U U

    : 1.

    ( ) ,122110 nnnnn axaxaxaxaxP +++++= K - , 0n naaaa ,,,,0 210 K= - (), U U, U nU. U U ( ).

    2.

    ( )mm

    mmnn

    nn

    bxbxbxbaxaxaxaxR ++++

    ++++=

    11

    10

    11

    10

    KK

    U U. U U

    3. , , U U.

    4. , , U U.

    5. U U ( ). u, u x, x.

    ( )uFy = ( )xu = . x

  • ( )[ xFy ]= - U U. . U

    U B1B, B2B, , xBnB, , > 0 N = N(), N. axnn

    =lim . , ax .

    ( )xfy = .

    1. U ( )xfy = b ( by ) U ( ax ), > 0 > 0, ,

    0, , Nx >

  • 2. . .

    U

    ,

    , ax x . ax , x , .

    1. , : ( ) kaxaxaxkax uuuuuu +++=+++ lim...limlim...lim 2121

    2. , .

    kk uuuuuu lim...limlim...lim 2121 = .

    : .limlimlimlim,lim 11111 ucuccuau === .

    3. , 0:

    vu

    vu

    limlimlim = 0lim v .

    4. )();();( xvvxzzxuu ===

    vzu , u v ax x b, z = z(x) ax ( x ) .

    5. ax ( x ) y , b .

    0y by 0b

    6. ) v=v(x), (xuu = ax

  • ( x ) ) ,

    ()( xvxu

    )(lim)(lim xvxuaxax .

    7. v , .. , , , .. v < M,

    , < M. av =lim

    -0, - . { } { } { } 1,,0,,00 U.

    x

    xsin (U 0x

    U) 1sinlim0

    = xx

    x.

    U e.

    1. U U n

    n

    + 11

    U :n U = nlim

    n

    n

    + 11 . .

    : =2, 7182818284...

    . x

    x

    + 11 , , :

    xlim

    x

    x

    + 11 = .

  • 3. , . . . . . .

    U , = )(xfy

    . 1. )(xf x , .. U

    U, >0, > 0, , )( .

    )(xf ax , = )(lim xfax . )(xf , , +)(xf , , - )(xf .

    2. ) U (xf U ,

    , , ,

    0>M.)( Mxf

    , U)(xf U .

    3. ) U (xfx a ,U , .

    4. ) U (xfx , U , ,

    0>N

  • Nx >|| , ) . (xf 1. ( ) bxf

    ax=lim b ,

    ) (xf ax . 3.

    , )(xf

    ( ) = xfaxlim ( ) = xfxlim , .. , .

    )(xf

    U 1. )(x U

    U ax U U x , 0)(lim = xax , 0)(lim = xx . 1. 0)( = x ax ( x )

    0, 1=y . 2.

    . 3. )(x

    )(xzz = ax ( x ), .

    C 1. 0lim = , 0lim = , lim 0= . 2. 0lim = , constc = , 0lim =c . 5. UU

    )()(

    xzx

    )(x , 0, .

    U

    ,

    , , .

  • 1. / , .. constAconst

    ax==

    ,0/lim ,

    , 0/1/lim = Aax , U .U

    2. / , .. 0/lim = ( = /lim ), U , ,U U , .U

    3. U k- ,U , .. k

    limax / .0= Ak

    4. / , .. 1/lim = ax , U U ( ~ ).

    U = f(x) B0B B0B.

    B0B = f(xB0B). =B0B +, . , :

    B0 B+ = f(xB0 B+). = f(xB0B+)

    f(xB0B). . = f(x) U =UBU0 UBU( UBU0UBU),U B0B

    0lim0

    = yx

  • , , 0)]()([lim 00

    0=+ xfxxfx .

    )()(lim 00

    0xfxxf

    x=+ .

    . = f () U UBU0U B: 1) B0,B 2) , , )(lim

    00xf

    xx +)(lim

    00xf

    xx 3)

    )(lim00

    xfxx +

    = = f (B0B). )(lim00

    xfxx

    , B0B = f () U.U =B0B U .U

    . = f () ,

    )0()(lim 000

    +=+

    xfxfxx

    )0()(lim 000

    =

    xfxfxx

    ,

    1) , = B0 B U )(lim)(lim00 00

    xfxfxxxx +

    1- U,

    )(lim)(lim00 00

    xfxfxxxx +2) = ,

    = B0B, = B0B U U. , U U.

    U

    1. = f ()

    [a,b], [a,b] =B1B , f ( B1B) f (), , =B2B ,

  • f (B2B) f (). f (B1B) U U = f () [a,b], f (B2B) U U = f () [a,b].

    2. = f () [a,b], , a b =, .

    3. = f () [a,b]. f ()= , f (b) =B, , , =, b , f ()= .

  • 4. . , . . . . . .

    y ,

    , x , x 0, ..

    xxfxxf

    xy

    xx +=

    )()(limlim 00

    00

    U Uf(x) x.

    .,),(dxdyyxf

    U. ,

    =f (x) , . U .

    y=f(x) xB0B, ..

    x

    xxfxy

    xx +=

    )(limlim 0

    00, f(x)

    U xUBU0UBU.U [a ,b], U U[a, b].

    . f(x) xB0B, U U .

    , , , , , .. .

    U

    1. 0, .. , = const , cy = 0=y .

    2. , ..

  • )(xcfy = , = const , )(xfcy = . 3.

    , ..

    )()( xvxuy += , )()( xvxuy += . 4.

    , ..

    ,vuy = uvvuy += . 5.

    , , , ..

    vuy = ,

    2vuvvuy= .

    U

    =f(x), .. , : y=F(u), u =(x) y=F((x)).

    y=F(u) u .

    . u=(x) x )(xux = , F(u) u

    )(uFyu = , y=F((x)) x ,

    )()( xuFy xux = , u u=(x).

    U

    1. , consty = 0'=y . 2. , . nxy = 1' = nnxy

  • 3. xy = , 1'=y . 4. xy = ,

    xy

    21'= .

    5. x

    y 1= , 2

    1'x

    y = . 6. , xy sin= xy cos'= . 7. xy cos= , xy sin' = . 8. , tgxy =

    xy 2cos

    1'= .

    9. , ctgxy =x

    y 2sin1' = .

    10. , xy arcsin=21

    1'x

    y

    = .

    11. yy arccos= , 21

    1'x

    y

    = .

    12. , arctgxy =21

    1'x

    y += .

    13. , arcctgxy =21

    1'x

    y += . 14. , . xay = aay x ln'=15. , xey = xey =' .16. , xy alog= exy alog

    1'= .

    17. , xy ln=x

    y 1'= .

    U 1. , )(xCuy = )(' xuCy = . 2. , )()( xvxuy += )()( xvxuy += . 3. , )()( xvxuy = )()()()( xvxuxvxuy += .

  • 4. )()(

    xvxuy = ,

    )()()()()(' 2 xv

    xvxuxvxuy= .

    5. ).(),( xuufy == )()( xufy xu = . 6. ,

    ==

    )()(

    yxxfy

    yx xxf

    '1)(' = .

    U ,

    )(xy)(),( txty == , t Tt

  • 5. . . . .

    U

    y=f(x) [a,b].

    , .lim)(0 x

    yxfyx

    == , , ,

    += y

    xy ,

    , .. 0 0. xxyy += .

    y , U , x U. xy UU dy.

    dy= xy . U

    .U. dxxfdy )(= .

    , dxdyxf = )( ,

    .

    U

    y=f(x) [a,b]. x. y

    , U .U y )(xf .

  • y . . VIV yy , , VIy

    n- f(x) (n-1)- . ) - .

    )(ny ( )1()( = nn yy

    6. , , .

    . 7. .

    .

  • 8.

    . . , , . . .

    , .

    .

    1. 1) f(x), [a,b], , [a,b] , .. 0)( xf .

    2) f(x) [a,b] (a,b), 0)( > xf x(a,b), [a,b].

    () , :

    2. 1) f(x), [a,b], , [a,b] . 0)( xf

    2) f(x) [a,b] (a,b), 0)(

  • 1 (

    ). f(x) x=xB1B , , .. f (xB1B)=0.

    , x.

    , , . .

    , : f () =0 () B B B.B f

    , f () =0 f () , .

    2. ( ). f(x) , xB1B ( , xB1B). + , x=xB1 B . +, x=xB1 B .

    , .

    1. , (a,b), .

  • 2. , (a,b), .

    1. (a,b) f`(x) , .. )(xf 0, .

    . , , .

    , .

    3. y=f(x). (a)=0 f f (a) x=a , x=a .

    . L , M , M L . 0

    .

    1. . , =+ )(lim 0 xfax = )(lim 0 xfax , x=a .

    x

    y yy

    x x 00 0

  • , , .

    x=a , ax f(x) , x=a . 2. .

    y=f(x) , : =kx+b.

    k b: ;)(limxxfk

    x = ].)([lim kxxfb x = , .

    , :

    1) ;

    2) ;

    3) (, , );

    4) (, );

    5) ( f (x)=0 f (x)`- );

    6) ( f (x)=0 (x) ); f

    7) ;

    8) ;

    9) , .

    .

  • 9. . . . . .

    : F(x)

    () (a, b), F(x) (a, b) ( ) ( )xfxF = dF(x)=(x)dx . ),( bax

    () F(x), .

    1. F(x) () (a, b), F() + C , C - .

    2. F(x) () () (a, b), : () F(x) = C . ),( bax

    . F(x) (), ( ) cxF + ()

    dxxf )( . F(x) (),

    : ( ) ( ) += cxFdxxf .

    () (). , , .

    1.

    ( )( ) ( )xfdxxf = . 2.

    : ( ) ( )dxxfdxxfd = .

  • 3. :

    dF(x) = F(x) + .

    ( )11

    .11

    ++=+ acaxdxx

    aa .

    ( )0ln.2 += xcxxdx . ( )1;0

    ln.3 >+= aacaadxa

    xx .

    cedxe xx +=.4 . += cxxdx cossin.5 . += cxxdx sincos.6 . += ctgxxdx2cos.7 . += cctgxxdx2sin.8 . + += cxcxxdx arccosarcsin1.9 2 . + +=+ carcctgxcarctgxxdx 21.10 .

    caxxax

    dx ++= 2222 ln.11 .

    ++= cxa xaaxa dx ln21.12 22 . 13.

    +

    +=

    cax

    cax

    xadx

    arccos

    arcsin

    22

  • +

    +=+ c

    axarcctg

    a

    caxarctg

    axa

    dx1

    1

    .14 22

    1.

    : ( ) ( ) = dxxfAdxxAf .

    2. :

    ( ) ( )[ ] ( ) ( )dxxgdxxfdxxgxf +=+ ( ).

    3. ( ) ( ) += cxFdxxf , ( ) ( ) ++=+ cbaxFadxbaxf 1 .

    , () , (t) (t) t.

    ( ) ( )[ ] ( )dtttfdxxf = . x = (t) ,

    , .

  • u = u(x) v = v(x)

    .

    = vduuvudv . .

    udv

    vdu, .

  • 10. . . .

    - :

    ( ) ( )( )xQxP

    xRm

    n= (m>n) :

    ( ) ( ) ( ) ( ) ( ) ...... 22211221 pslkmm qxpxqxpxxxxxaxQ ++++=

    :

    ( )( ) ( ) ( )

    ( ) ( ) ( ) +++++++++=

    ll

    kk

    m

    n

    xxB

    xxB

    xxB

    xxA

    xxA

    xxA

    xQxP

    22

    2

    2

    2

    11

    21

    2

    1

    1

    ...

    ...

    ( ) ( ) +++ +++++ ++++ ++ sSS qxpx NMqxpx NxMqxpx NxM 1122112 22112 11 ...( ) ( ) ...... 2222222 22222 11 +++

    +++++

    +++++ pPP

    qxpxqxpxqxpx+ QPQxPQxP

    22112121 ,,,,...,...,;,..., NMNMBBBAAA ek .. .

    , , .

  • 11. .

    1.

    , sinx cosx: ( ) dxxxR sin,cos .

    t. :

    txtg =2

    .

    sinx, cosx dx t dt;

    212;2

    tdtdxarctgtx +== .

    .12;

    11cos;

    t12tsin 22

    2

    2 tdtdx

    ttxx +=+

    =+= ,

    .

    2.

    . 1) ,

    sinx = t, cos xdx=dt

    ( ) xdxxR cossin( ) .dttR

    2) ,

    cosx = t, sin x dx= dt .

    ( ) xdxxR sincos

  • 3) tgx,

    tgx = t , 21,

    tdxarctgtx +==

    dt

    . 4) , sinx cos x

    , dxxxR )cos,(sin

    tgx = t. 5) .

    . xdxx nm cossin

    ) , m n ,

    xdxx nm cossin

    . , n . n=2+1 :

    .cos)sin1(sin

    coscossincossin2

    212

    xdxxx

    xdxxxxdxxpm

    pmpm

    ===

    +

    sinx = t, cos xdx=dt. ,

    xdxx nm cossin = ( ) ,1 2 dttt pm t.

    ) , m n . xdxx nm cossin m =2p, n =2q.

    :

    ).2cos1(21cos),2cos1(

    21sin 22 xxxx +==

    ,

    += + .)2cos1()2cos1(2 1cossin 22 dxxxxdxx qpqpqp , ,

    cos 2x . , ). .

  • , .

    mn xx ,1. R(x, , ) k 1/m, 1/n, ...

    x= ., 1dtktdxt kk =

    t t.

    2.

    ++

    ++ ;...;; nm

    dcxbax

    dcxbaxxR .

    ,

    . :

    ,Ntdcxbax =+

    + N m, n,

  • 12. . . . -. . : , , .

    , .

    y = f(x) [a,b], f(x) >0. , , y = f(x), : x = a x = b.

    , [a,b] .

    . ,

    SBnB, [ ]ba, ( ):

    . (1) =

    =1

    00max

    )(limn

    kkkx

    xfSk

    - . kxmax

    f(x) [ ]ba, k .

    . (1) ,

    0max kx

    k , f(x) [ ]ba, :

    b

    a

    dxxf )( .

  • , b . , :

    =

    =1

    00max

    )(lim)(n

    kkkx

    b

    a

    xfdxxfk

    . ,

    f(x) a b.

    .

    ,

    abdxb

    a

    = . =a

    b

    b

    a

    dxxfdxxf )()( , a=b, . 0)( =aa

    dxxf

    , , . [ ba, ]

    1.

    :

    = ba

    b

    a

    dxxfAdxxAf )()( .

    2. f(x) g(x) [ ]ba, , :

    [ ] +=+ ba

    b

    a

    b

    a

    dxxgdxxfdxxgxf )()()()( .

    3. [ ]ba, , ( a, b, ).

  • += bc

    c

    a

    b

    a

    dxxfdxxfdxxf )()()( .

    4. 0 )( xf [ ]ba, (a

  • :

    = xa

    dttfx )()( ( )bxa . . f(x) [ ]ba, ,

    ) [ , (x ]ba,)()( xfx = .

    -.

    . f(x) [ ]ba,

    F(x) - f(x) [ ]ba, , :

    )()()( aFbFdxxfb

    a

    = . -. baxFaFbF )()()( = - .

    u(x) v(x) . [ ba, ]

    = ba

    ba

    b

    a

    vduuvudv .

    , , .

  • , f(x)

    .

    ba

    dxxf )(

    )(tx = . :

    . : 1. f(x) [ ]ba, . 2. )(t )(t [ ] ,

    bta )( t ba == )(;)( . 3. [ ])(tf [ ] ,

    [ ] =

    dtttfdxxf

    b

    a

    )()()( .

    1. 0 )( xf [ ]ba, ,

    S= . b

    a

    dxxf )(

    2.

    [ ] dxxfsb

    a += 2)(1 .

    3. y = f(x) Ox

    [ ]=b

    ax dxxfV

    2)( .

  • 13. . .

    , : b

    a

    dxxf )(

    1. [ ]ba, . 2. f(x) [ ]ba,

    ( ). ,

    .

    ( )

    1. f(x)

    +

  • +=

    a

    a

    dxxfdxxfdxxf )()()( .

    , , , , .

    , . .

    1. [ )+ ,ax :

    )()(0 xgxf , :

    1. , . +a

    dxxg )( +a

    dxxf )(

    2. , . +

    a

    dxxf )( +a

    dxxg )(

    ( )

    f(x) [ ]ba,

    ( ), d ,

    f(x) . a b .

    [ ]ba,

    ++= bd

    d

    c

    c

    a

    b

    a

    dxxfdxxfdxxfdxxf )()()()( .

    .

  • 0 , :

    =b

    a

    b

    a

    dxxfdxxf )()(lim0

    .

    , .

    . f(x) bxa < , = ,

    .)(lim)(0 +=

    b

    a

    b

    a

    dxxfdxxf

    .

    2. bxa

  • II

    14. . , . , .

    .

    (, ), , z, z :

    z = f (x, y). : z =ln ( )222 + yx .

    z. D z. (, ) (, ).

    . - MB0B (B0B,B0B) MB0.B - MB0B (B0B,B0B)

    2200 )()( yyxx + < ..

    B1 B D, , .

    B2 B D, D, .

    D .

    D ( D ), . D , .

    z = f (, ) , ..

  • z = f (,) D.

    , . n=2.

    . f (, ) B0B, y B0 B ( B0B), >0 B B> 0 , - B0 B( B0B,B BB0B)

  • ),(),(lim 000

    0yxfyxf

    yyxx

    =

    f (, ) , .

    B1B(B1B, B1B) f (, ), , B1 B .

    z =f (, )

    B0B (B0B, B0B) . = B0B, . z =f (, B0B). B1B( +, B0B).

    BB z = f (B1B) - f ( B0B)= f ( +, B0B) - f (B0B,B0B). z

    BB z.

    . xzx

    0 , z B0B (B0B, B0B).

    xz , , ),( 00 yxf x xz ,

    xyxf

    ),( 00 . ,

    xz =

    xzx

    x

    0lim =

    =x

    yxfyxxfx

    +

    ),(),(lim 0000

    0= . ),( 00 yxf x=

    : , .

  • B0B(B0B, B0B) B2B(B0B, B0 B+) z ( = B0B, : z= f(B0B, )).

    z = f (B2B) - f ( B0B)= f ( B0B ,yB0B+ ) - f (B0B,B0B). y.

    yzy

    0, , z .

    yz , , ),( 00 yxf y yz ,

    yyxf

    ),( 00 .

    yz =

    yzy

    y

    0lim = yyxfyyxf

    x +

    ),(),(

    lim 00000

    = . ),( 00 yxf y

    xz

    yz

    z B0B (B0B, B0B) .

    , .

    yz ,

    L :

    tgyz

    M =

    0.

    xz

    z =f (, )

    =B0B, .. tgxz

    M =

    0.

  • 15. . . , . .

    f (x,).

    B0B(B0B ,B0B) . B0B(B0B ,B0B) ( ,)

    B B= xB0B+ x, = B0B+ :

    z = f () - f (B0B) = f (xB0B+ x, B0B+ ) - f (xB0B, B0B), .. , , , .

    z = f (x, ) B0 B(B0B,B0B), , :

    z = x + y + , 0 0 . x + y x

    y f (x, ) B0 B(B0B,B0B)

    dz = x + y. :

    d z = xz x +

    yz y. x =d y= d.

    d z = ),( yxf x d x + ),( yxf y d y ( (, ). , d z = z + z - .

    xd yd

    .

  • .

    z = f (u, v), u v , , :

    u (x, ) v (x, ) z

    , x :

    z = f [u(x, ), v(x, )].

    xz

    =xv

    vz

    xu

    uz

    +

    ;

    yz

    =yv

    vz

    yu

    uz

    +

    .

    1. :

    ),,,( zyxfw = ).();();( tzztyytxx === , , ),,,( zyxfw =

    t: w=w(t),

    dtdw =

    dtdz

    zw

    dtdy

    yw

    dtdx

    xw

    +

    + -

    .

    2. , .

    ),,,,( zyxtfw = ).();();( tzztyytxx ===

    dtdw

    =dtdz

    zf

    dtdy

    yf

    dtdx

    xf

    tf

    +

    ++

    1 -

    .

  • .

    z = f (u,v), u =u (x, ), v =v (x, )

    .

    =dz dvvzdu

    uz

    +

    . ,

    , u v . ,

    , u v . .

    z = f (u,v).

    :

    ),( yxfxz

    x= ),( yxf

    yz

    y= .

    , , : . . :

    ),(22

    yxfxz

    xxz

    xx=

    =

    ; ),(2

    yxfxz

    yyxz

    xy=

    =

    ;

    ),(2

    yxfyz

    xxyz

    yx=

    =

    ; ),(22

    yxfyz

    yyz

    yy=

    =

    .

    ),( yxf yx , ),( yxf xy , .

  • , .

    . ,

    xyz

    2 = yxz

    2 .

    =dz dxyxf x ),( + dyyxf y ),( .

    .

    [ ]dzdz =2d .

    =zd 2 2),( dxyxf xx +2 dxdyyxf xy ),( + . 2),( dyyxf yy

    ,

    F(x,y,z)=0, D z= f(x,y), : F(x,y, f(x,y))=0.

    , :

    0=+ xzxx zFxF , .. 0=+ xzx zFF

    ),,(),,(

    zyxFzyxF

    zz

    xx

    = . :

    ),,(),,(

    zyxFzyxF

    zz

    yy

    = . ,

    0),,( zyxFz .

  • 16. , . . .

    :

    u=f(x, y, z).

    xu

    , yu

    , zu

    . : lB0B, .

    B0B(xB0B,yB0B,zB0B) 0l

    r.

    B1B(B0B+ x, yB0B+ y, zB0B+ z) 222 zyx ++=

    B0 . B B0B B1B u=f(M) u= f(MB1B) f(MB2B).

    ),,(),,( 000000 zyxfzzyyxxfu +++= , , u = f(M) B0B l .

    : lu ; lu ; lu r ; l

    ur .

    , :

    ),,(),,(

    lim 0000000

    zyxfzzyyxxulu +++=

    .

  • .

    0lr

    :

    { } cos,cos,cos0 =lr .

    coscoscoszu

    yu

    xu

    lu

    +

    +=

    .

    u=f(x,y,z) { } cos,cos,cos0 =lr rrr

    . kji ,, .

    u=f(x,y,z). MB0B(xB0B,yB0B,zB0B) B0B , .

    . .

    u=f(x,y,z) MB0B(xB0B,yB0B,zB0B) . B0B :

    zzyxf

    yzyxf

    xzyxf ),,(;),,(;),,( 000000000 .

    B0B, . grad )(Mu 0

  • grad . ),,( 000 zyxf ,

    kzuj

    yui

    xuMu

    rrr+

    +=)(grad .

    .

    ,

    (2 = ) , ..

    . . u=f(x,y,z)

    B0B(xB0B,yB0B,zB0B) , . .

    .

    z= f(x,y), B0B(xB0B,yB0B) .

    B0B(xB0B,yB0B)) z = f(), B0 (0< d (MB0 BM) < )

    f () 0. .

    : B1B B0.

  • . ( ). z= f(x,y) B0B(xB0B,yB0B) ,

    0),( 00 = yxf x ; 0),( 00 = yxf y . ,

    , .

    (). , . .

    . z= f(, ) B0B (B0B ,B0B), B0B

    0),( 00 = yxf x ; 0),( 00 = yxf y (.. B0B ). :

    Ayxf xx = ),( 00 , Byxf xy = ),( 00 , Cyxf yy = ),( 00 . :

    1. = >0, B0B (B0B ,B0B) f(, ) , , < 0 , > 0.

    2BAC

    2. =

  • 17. . . .

    . z

    =x+iy, x y , i : iP2P= 1.

    y , , z : x = Re z , y = Im z.

    1) z = x + iy.

    zB1B = xB1B + iyB1B zB2B = xB2B + iyB2B (zB1B = zB2B) ,

    xB1B = xB 2B, yB1B = yB2B.

    z z ,

    z = x + iy, z = x i y.

    2) r - - z ,

    O. (. 1). r , ,

    z :

    r = | z |; = Arg z.

    r = | r | 22 yx += .

    xytg = .

    z: ) Arg( Arg +

  • , , 2.

    Arg z : ( ) ( ) 20

  • : ( ) ninrz nn sincos += . ) . n- z

    w (w= n z ), wPnP=z. z w : ( ) sincos irz += ( ).sincos iw += .

    ( ) ( )( ).102 , sincossincos, ,...,kknr irninzwnnn

    =+==+=+=

    : = n r -

    r, =n

    k 2+ (k= ,...2,1,0 ).

    .2sin2cos

    +++==n

    kin

    krzw nnk

    , z 0 n n, .

  • 18. . . . .

    . , , = f(x) .,...,, )(nyyy

    :

    .0),...,,,,( )( = nyyyyxF = f(x)

    , . .

    , .

    . = f(x), , , .

    .0),,( =yyxF

    ,y = f(x, ). , .

    .

    = (, ), :

    ) ;

    ) = B0B = B0B, = B0B, = (, B0B) .

    (, , ) = 0,

  • . .

    . = (, B0B), = (, ), . (, , B0B)=0 .

    , . . , .

    ),()( 21 yfxfdx

    dy = (1) , , , . , (, )0)(2 yf :

    .)()(

    11

    2dxxfdy

    yf= . (2)

    , , , . , ,

    += Cdxxfdyyf )()(1 12 . (2) , (1) .

  • 19. . . .

    . f(x, y)

    n- ,

    f( x, y) = f( x, y). n.

    ),( yxfdxdy =

    , f (x, y) .

    x/1= .

    .

    .

    )()( xQyxPdxdy =+ , (3)

    ) - . )(xP (xQ

    : = u (x) v (x) .

    , (3).

    .

  • 20.

    . . . , .

    n-

    0),...,,,,( )( = nyyyyxF , n- ,

    ),...,,,,( )1()( = nn yyyyxfy . .

    n- ),...,,,( 21 nCCCxy = ,

    n , : nCCC ,...,, 21)

    ; nCCC ,...,, 21)

    ,00 yy xx == ,00 yy xx = = ... , )1(0)1( 0 = = nxxn yy , nCCC ,...,, 21

    ),...,,,( 21 nCCCxy = . 0),...,,,( 21 =nCCCx

    . ,

    , .

    nCCC ,...,, 21

    ,

    1.

    ),(2

    2

    dxdyxf

    dxyd = ,

  • .

    pdxdy = .

    dxdp

    dxyd =2

    2.

    ,

    ),( pxfdxdp =

    . ,

    = (, B1B), pdxdy =

    . += 21),( CdxCxpy 2.

    ),(2

    2

    dxdyyf

    dxyd = ,

    .

    pdxdy = ,

    .

    .2

    2p

    dydp

    dxdy

    dydp

    dxdp

    dxyd ===

    ,

    ),( pyfdydpp = .

    , B1B:

    = (, B1B). ,

    , .

  • 21. . . . .

    . n- , , .. )(,...,, nyyy

    )(...)1(1)(

    0 xfyayaya nnn =+++ , (4)

    ) - , , . ,

    ,

    naaa ,...,, 10 (xf00 a

    naaa ,...,, 10 )(xf10 =a ( 1,

    ). ) , , .

    (xf

    ) 0,

    (xf .

    ) 0, (xf0...)1(1

    )( =+++ yayay nnn .

    1. B1 B B2 B

    021 =++ yayay , B1 B+B BB2B .

    2. B1 B , B1 B .

  • . (4) B1 B B2 B [,b], , .. const

    yy

    2

    1 .

    .

    3. B1 B B2 B (4),

    =B1B B1 B+B BB2 BB2B B1B B BB2 B , .

    0=++ yqypy , (5) p q .

    kxey = , k = const;

    .; 2 kxkx ekykey ==

    (5), .02 =++ qpkk (6)

    (6) (5). , ; kB1B B BkB2B.

    qppkqppk =+=42

    ,42

    2

    2

    2

    1 .

    : 1. kB1B B BkB2B

    ; 2. kB1B B BkB2B ; 3. kB1B B BkB2B .

  • . 1. : kB1B B BkB2B.

    xkxk eCeCy 21 21 += .

    2. . kB1B= B BkB2.

    )( 2121 111 xCCexeCeCy

    xkxkxk +=+= .

    3. . ,

    ,, 21 ikik =+= .

    4,2/

    2pqp == (5)

    )sincos( 21 xCxCey

    x += , B1B B2 B- .

    ).(21 xfyayay =++ (7)

    : .

    - * y

    .021 =++ yayay

  • = y + * (8) (7).

    )(xfqyypy =++ , (9) p q - .

    , .

    1. (9) , ..

    ( ) xn exPxf )(= , - n . : )(xPn

    ) k .02 =++ qpk

    x

    n exQy)(= .

    ) :

    xn exxQy

    )(= . )

    : x

    n exQxy)(2= .

    2. xexQxexPxf xx sin)(cos)()( += ,

    - , :

    )(),( xQxP

    ) + i , (9)

  • xexVxexUy xx sin)(cos)( += , - , ;

    )(),( xVxU)(),( xQxP

    ) + i , (9)

    ]sin)(cos)([ xexVxexUxy xx += . ,

    , (9) , ..,

    )(),( xQxPxexP x cos)( xexQ x sin)( .

    , .

    . (, ), , z, z : z = f (,) D.

    z =f (, ) 0 (0, 0) . = 0, . z =f (, 0). 1( +(, 0). ( z = f (1) - f ( 0)= f ( +(, 0) - f (0,0). z ( z. . ((0 , z 0 (0, 0). f (x,). 0(0 ,0) . 0(0 ,0) ( ,) ,