Matrici i Determinanti

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Predavanje na finki za matrici i determinanti

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  • 1:

    1

    1. 1. 1.1 1. . m n , P

    mxn P. ij , i -

    , - ij.

    Amxn = [aij]mxn , (i=1,...,m;j=1,...,n)

    mxn. (A)ij i- j- A. :

    3x2, B 3x3, C 3x1. 2: . , m=n n, n. B 3. mxn = [aij]mxn . m =1, A1xn =[ a12 a12 . . . . a1n] - n=1 ,

    - .

    =

    mnmm

    n

    n

    aaa

    aaaaaa

    A

    ..............

    ......

    21

    22221

    11211

    =

    1

    21

    11

    1

    .

    .

    m

    mx

    a

    aa

    A

    +=

    =

    =

    ii

    iCBA

    2

    1,

    752021435

    ,52302/11

  • 1:

    2

    n=

    nnnn

    n

    n

    aaa

    aaaaaa

    KKKKKKK

    21

    22221

    11211

    i=j , aij

    i=1,,n, .

    , , , .

    3. . Amxn = [aij]mxn e . -Amxn = [-aij]mxn .

    4. . , mxn Omxn.

    5. . Dn = [dij] 0, dij=0 za ij, .

    6. . C , d11=d22=. . . =dnn=c C

    n.

    =

    c

    cc

    Cn

    ......0.........0...000...00

    7. . nxn, 1 n En In E, I .

    , 3,

    =

    100010001

    3I .

    8. . A = [aij]mxn. () A () A

    =

    nn

    nxn

    d

    dd

    D

    0......0..........0...000...00

    22

    11

  • 1:

    3

    AT A'. A'=[a'ij]nxm A=[aij]mxn a'ij = aji (AT)ij=(A)ji. :

    9. . A = [aij]mxn B = [bij]pxq , m=p n=q aij=bij i=1,2,...,m; j=1,2,...,n. :

    2x-y=1 x+y=2 x-y=0 x+3y=4. 1.1 , (AT)T = A . : Amxn=[aij]mxn ATnxm =[aij]nxm a'ij = aji. (AT)T=[aij] mxn, aij=aji=aij. 10. . n, Anxn aij=aji i,j=1,2,...,n; .

    1.2 S n, , ST=S. 11. . = [aij] n. aij=-aji . 1.3 An T = -A.

    =

    =

    241302

    ,210432 'AA

    =

    =

    322212

    312111

    3231

    2221

    1211

    aaaaaa

    Aaaaaaa

    A T

    =

    ++

    4021

    32

    yxyxyxyx

  • 1:

    4

    1.2 . , (+) () : a,b,c 1. a+b, ab ();

    2. a+(b+c)=(a+b)+c, a(bc)=(ab)c ( ); 3. a+b=b+a, ab=ba ( ); 3. , 0, (

    ) a, a+0=0+a=a;

    4. a3 b a+b=b+a=0. ( .) a a;

    5. , 1, ( ), a, a1=1a=a ;

    6. a, a0, b, ab=ba=1. ( 0, .) a-1.

    7. a,b,c, a(b+c)=ab+ac ( ).

    , (+,), . , P + () (), 1-7 . , (+,) Q(+,), C(+,) . Z2={0,1}, 2, :

  • 1:

    5

    + 0 1 0 1 0 0 1 0 0 0 1 1 0 1 0 1

    , . 12. . A=[aij] B=[bij] mxn, C=[cij] mxn cij A B cij = aij + bij (i=1,2, . . . ,m; j=1,2, . . . ,n) A + B = C

    :

    :

    C A B. 13. . A=[aij] mxn 3 C=[cij] mxn

    cij = aij (i=1,2, . . . ,m; j=1,2, . . . ,n) C = A.

    :

    (-1)A -A. 14. A B = A + (-1) B. A, B C ,3 3 :

    +++

    ++++++

    =

    +

    mnmnmmmm

    nn

    nn

    mnmm

    n

    n

    mnmm

    n

    n

    bababa

    babababababa

    bbb

    bbbbbb

    aaa

    aaaaaa

    ...............................................

    ......

    ........................

    ......

    .........................

    ......

    2211

    2222222121

    1112121111

    21

    22221

    11211

    21

    22221

    11211

    =

    =

    =3112

    ,010321

    ,025432

    CBA

    =

    ++=+

    015113

    001205342312

    BA

    =

    ==

    =

    082016128

    042454443424

    4,4,025432

    AA

  • 1:

    6

    1.4 A + B = B + A () 1.5 (A + B) + C = A + (B + C) () 1.6 A + O = O + A = A ( O A)

    1.7 A + (-A) = (-A) + A = O 1.8 (A + B) = A + B

    1.9 ( + ) A = A + A 1.10 () A = (A) 1.11 1 A = A 1.12 (A + B)T = AT + BT 1.13 (A)T = AT 15. A B mxn nxp C mxp,

    C= AB. ij i - A j- B. , . a11 a12 . . . a1n b11 . b1j . b1p . . . . . . b21 . b2j . b2p

    ai1 ai2 . . . ain . . . . . = . . . . . . . . . . .

    am1 am2 . . . amn . . . . . bn1 . bnj . bnp

    ===

    ===

    ===

    n

    kkpmk

    n

    kkjmk

    n

    kkmk

    m

    kkpik

    m

    kkjik

    n

    kkik

    m

    kkpk

    m

    kkjk

    n

    kkk

    bababa

    bababa

    bababa

    1111

    1111

    11

    11

    111

    ......

    .................

    ......

    ..................

    ......

    :

    ),...,2,1;,...2,1(1

    pjmibacn

    kkjikij ===

    =

    ++++++=

    232213212222122121221121

    231213112212121121121111

    232221

    131211

    2221

    1211

    babababababababababababa

    bbbbbb

    aaaa

  • 1:

    7

    : 1.14 (AB)C = A(BC) () : A mxn, B nxp C pxq . AB mxp, (AB)C mxq, BC nxq, A(BC) mxq. .

    ij

    n

    ssjis

    n

    s

    p

    kkjskis

    p

    k

    n

    skjskis

    p

    kkjikij

    BCABCA

    CBACBACABCAB

    ))(()(

    )()()())((

    1

    1 11 11

    ==

    ===

    =

    = == ==

    :

    1.15(A + B)C = AC + BC A(B + C) = AB + AC () ! AB BA. , . 16. . AB = BA A B . AB BA , C=AB-BA A B. 1.16 A = [aij] mxn , a D =[dii] nxn C = AD jjijij dac = . . A = [aij] mxn , a D =[dii] mxm C = DA cij=diiaij. , . : A = [aij] mxn , a D =[dii] nxn

    C = AD jjijn

    kkjikij dadac ==

    =1,

    dkj=0 kj. A = [aij] mxn , a D =[dii] mxm , C = DA ijii

    n

    kkjikij adadc ==

    =1,

    dik=0 ik.

    =

    ++++++=

    =

    =

    15125672

    023512250215033213220312

    ,010321

    ,2532

    BABA

  • 1:

    8

    1.17 A e mxn , a In Im , AIn = ImA = A.

    Ap = A A ...A (p=1,2,. . . ). 0=I. p

    1.18 Ap Aq = Ap+q

    1.19 (AB)T = BT AT. : A mxn, B nxp, AB mxp, (AB)T pxn . BT pxn, AT nxm, BTAT pxm . ,

    ijTT

    n

    kkj

    Tik

    Tn

    kik

    Tkj

    Tn

    kkijkjiij

    T BAABBABAABAB )()()()()()()()())((111

    ===== ===

    17. . A () B

    AB=BA=I. . :

    .

    1.20 . : AB=BA=I AC=CA=I.

    B=BI=B(AC)=(BA)C=IC=C.

    B=C, A . , A-1. ,

    =

    =

    5273

    3275

    ,1001

    3275

    5273

    ,1001

    5273

    3275

    imatricite

  • 1:

    9

    21 (A-1)-1=A 22 A B , AB

    (AB)-1=B-1A-1. : A B .

    (AB)(B-1A-1)=A(BB-1)A-1=AA-1=I, (B-1A-1)(AB)=B-1(A-1A)B=B-1B=I.

    2.2 2.2.1 mxn :

    1. () . 2. ()

    . 3. ()

    (). 2.2.2 . B A A B A~B. 2.2.3 . In . Eij i- j- . Ei() i- . Eij() j- i- . Eij, Ei() Eij() , , , : Eij = Eij, Ei() = Ei() Eij() = Eji() 2.2.1 3:

    =

    =

    =

    100010201

    200010001

    100001010

    )2(13)2(312 EEE

  • 1:

    10

    2.2.2.

    =

    100001010

    1E

    . A B

    E1A E1B. :

    2.2.3

    =

    =

    =

    100010201

    200010001

    100001010

    ' )2(13)2(312 EEE

    2.2.1 Eij, Ei() Eij(), Eij, Ei() Eij().

    : A mxn, Im m. Eks k- s- . ,

    ik,s eij=

    =

    jiji

    ,1,0 ekj=

    =

    sjsj

    ,1,0

    i esj=

    =

    kjkj

    ,1,0

    .

    B=EksA, B, j{1,,n} :

    ik,s bij= ijijiim

    lljil aaeae ==

    =1,

    sjsjks

    m

    lljklkj aaeaeb ===

    =1, kjkjsk

    n

    lljslsj aaeaeb ===

    =1

    B k- s- A. Ek() k- . ,

  • 1:

    11

    ik, eij=

    =

    jiji

    ,1,0 ekj=

    =

    kjkj

    ,,0

    . B=Ek() A, B j{1,,n} :

    ik, bij= ijijiim

    lljil aaeae ==

    =1, kjkjkk

    m

    lljklkj aaeaeb ===

    =1,

    B k- A . Eks() s- k- . , ,

    ik eij=

    =

    jiji

    ,1,0 ekj=

    ==

    sjkj

    skj

    ,,1

    ,,0

    .

    B=Eks() A, B j{1,,n} : ik, bij= ijijii

    m

    lljil aaeae ==

    =1,

    sjkjsjkskjkk

    m

    lljklkj aaaeaeaeb +=+==

    =1,

    B s- k- A. A nxn . 2.2.2 A B mxn , A ( )

    B 1, 2, . . . , k B = EkEk-1E2E1A, ( B = A E1E2Ek).

    : A B, B A k . . B = EkEk-1E2E1A 1, 2, . . . , k B = EkEk-1E2E1A B A . 2.2.3 ()

    ,

  • 1:

    12

    (Eij)-1 = Eij, (Ei())-1 = Ei(1/) (Eij())-1= Eij(-). 2.2.4 A=[aij] mxn

    () mxn

    =

    0..0...000........0..0...000

    ......000.........

    ......0......

    222322

    11131211

    rnrr

    nr

    nr

    bb

    bbbbbbbbb

    B bii0 i=1,. . . , r.

    2.2.5 A=[aij] mxn mxn

    )()()(

    )(

    rnxrmxrrm

    rnrxr

    OOOI

    ., Ir r. 2.2.6

    , .

    2.2.7

    . 2.2.8 .

    , , -1.

    : A () . , Ek . . . E2 E1 A = I, Ei i{1, 2, . . . ,k} , -1 Ek . . . E2 E1 AA-1 = I A-1 Ek . . . E2 E1 I = A-1

    A. , , , A.

  • 1:

    13

    2.2.4: =

    011111121

    .

    : , [A|I] :

    -1=

    110011

    111. -1=I

    .

  • 1:

    14

    2.3 2.3.1 .

    A=[aij] n, tr A,

    , : 2.3.1 tr A = trA

    , 2.3.2 tr AT = tr A.

    A .

    a11a22-a12a21

    2.3.1

    . A 3.

    =

    =n

    iiiaAtr

    1

    =2221

    1211

    aaaa

    A

    103)2(414321

    det,4321 ====

    = AAA

    =

    333231

    232221

    131211

    aaaaaaaaa

    A

    211222112221

    1211det aaaaaaaa

    AA ===

  • 1:

    15

    . , , -.

    , , , . , . . 123, , . 123, 132, 231, 213, 312 321. , , 123, 231 312 , , 132, 231 321, . . , . 2.3.2 . S n .

    S S . , S={a,b,c}

    S. S n 1,2,...,n,

    =

    =

    abccba

    gacbcba

    f ,

    .

    det

    312213322113332112

    312312322311332211

    333231

    232221

    131211

    aaaaaaaaa

    aaaaaaaaaaaaaaaaaa

    A

    +

    +==

    .332112322311312213

    322113312312332211

    3231

    2221

    1211

    333231

    232221

    131211

    aaaaaaaaa

    aaaaaaaaaaaaa

    aa

    aaaaaaaaa

    ++=

  • 1:

    16

    S, S 1,2,...,n. ,

    , I= (i1, i2, i3, . . . , in), ik {1,2,3,...,n}. 1 n. 2.3.3 n

    123n=n! 2.3.3 . i, j

    , i j, i>j.

    , 2413 2, 1 , 4 , 1 4, 3 . , ? . . 2 2, 2. .. . , 35142 2 , 3 ( ), 0 , 1 , 2+3+0+1=6. 2.3.4. .

    , . I= (i1, i2, i3, . . . , in) Ip .

    , 35142 , 6 , 12345 0 , , 21345 . 2.3.4 ,

    , , , .

    niiiin

    ......321

    321

  • 1:

    17

    , n. 2.3.5 .

    n, A n , ( ). ,

    +, (i1, i2, ..., in) -, .

    I=(i1, i2, . . . ,in) {1,2,...,n}, a Ip . det A. , , n!, n!/2 n!/2 . , , , .

    =

    mnmm

    n

    n

    aaa

    aaaaaa

    A

    ..............

    ......

    21

    22221

    11211

    nniiiaaa ...

    21 21

    =

    ==),...,,(

    21

    21

    22221

    11211

    21

    21...)1(

    ............

    ...

    ...

    detn

    n

    p

    iiiIniii

    I

    nnnn

    n

    n

    aaa

    aaa

    aaaaaa

    A

  • 1:

    18

    2.3.5 det AT = det A.

    : . , . 2.3.6 ( ) ,

    . : , 1 ( ) . . .

    A. (i1, i2, ..., ik, ..., ij, ..., in), . 1 (i1, i2, ..., ik, ..., ij, ..., in), ik ij, - - . , 1 . det A1 = -det A. 2.3.2:

    2.3.7 ( )

    .

    : , , , . , det A = -detA, , det A=0. 2.3.8 - n- ,

    , .. akj=bkj+ckj, (j=1,2,...,n), 1

    njk nijikiiiaaaaa .........

    21 21

    362141051

    141362051

    =

  • 1:

    19

    2 , - , 1 bk1, bk2, ..., bkn, 2 ck1, ck2, ..., ckn.

    : ,

    A1 A2. 2.3.9 ( )

    , .

    : A=[aij] 1 - .

    2.3.10 ( ) .

    : , . 2.3.11 D , det D = a11a22...ann.

    2.3.12

    , . : 2.3.8,

    nknk

    nkknk

    nikiiinikiii

    nikikiiinikiii

    acaaabaa

    acbaaaaaa

    ............

    )......(......

    2121

    2121

    2121

    2121

    +=+=

    AaaaaaaaaAI

    kikiiiI

    Inikiii

    Ink

    p

    nk

    p det......)1(......)1(det2121 21211

    ===

  • 1:

    20

    , . 2.4 2.4.1 , . aij,

    i- j- n, Aij n-1 i- j- . ( n-1) aij Aij Mij=detAij. ( ) aij

    a*ij = (-1)i+j det Aij= (-1)i+j Mij

    2.4.1:

    2.4.1 A ,

    aij, , = ijij aaAdet .

    A

    aaa

    aaa

    aaa

    aaaaaa

    aaa

    aaa

    aaa

    aaaaaa

    aaa

    aaa

    aaa

    aaaaaa

    aaa

    aaa

    aaa

    aaaaaa

    aaa

    aaa

    aaaaaa

    aaaaaa

    nnnn

    jnjj

    jnjj

    n

    n

    nnnn

    jnjj

    knkk

    n

    n

    nnnn

    jnjj

    jnjj

    n

    n

    nnnn

    jnjj

    knkk

    n

    n

    nnnn

    jnjj

    jnknjkjk

    n

    n

    det

    ...........

    .............

    ............

    ...

    ...

    ...........

    .............

    ............

    ...

    ...

    ...........

    .............

    ............

    ...

    ...

    ...........

    .............

    ............

    ...

    ...

    ......................

    ......................

    ...................

    .....

    .......

    21

    21

    21

    22221

    11211

    21

    21

    21

    22221

    11211

    21

    21

    21

    22221

    11211

    21

    21

    21

    22221

    11211

    21

    21

    2211

    22221

    11211

    =+

    =+=+++

    3331

    2321

    3331

    23212112

    3331

    232112

    333231

    232221

    131211

    )1(,,aaaa

    aaaa

    aaaaa

    Aaaaaaaaaa

    A ==

    =

    = +

  • 1:

    21

    : i=j=1.

    1111)...(

    211)...(

    212

    2

    21

    21...)1(...)1(det MaaaaaaaA

    n

    n

    p

    n

    n

    p

    iinii

    I

    iiiniii

    I === 11 . i- , j- , aij , i-1 . . , j- j-1 . . 1 ,

    AAA jiji det)1(det)1(det 111++ == . 1 aij

    (1,1) ,

    ++ === ijijijijjiji aaMaAA )1(det)1(det 1 .

    2.4.2

    ( ) . ,

    : 2.3.8, i- n-1 , aij=0+. . . +0 +aij+0. . . +0,

    = ijij

    nnnjnn

    ij

    nj

    aa

    aaaa

    a

    aaaa

    ..............

    0...00..00........

    ......

    21

    111211

    i{1,2,. . . n}. ++= ininii aaaaA ....det 11 .

    : aij A Aij n-1, ( i-) ( j-) .

    = =

    +

    = =+

    ==

    ==n

    j

    n

    jijij

    jiijij

    n

    i

    n

    iijij

    jiijij

    MaaaA

    iliMaaaA

    1 1

    1 1

    )1(det

    )1(det

  • 1:

    22

    i- ( j- ) , . , . !

    . aij aij* : 2.4.3

    : ' i-

    k- , 2.3.12, ' . ', i-

    2.4.4 A B , det (AB) = det A det B. 2.4.2 . A*

    (i,j) aij* aij A. (A*)T A.

    2.4.5 A=[aij] n,

    A(A*)T=(A*)TA=AIn

    ==+++

    ==+++

    sjakosjakoA

    aaaaaa

    ikiakokiakoA

    aaaaaa

    nsnjsjsij

    kninkiki

    0det

    ...

    0det

    ...

    221

    2211

    .0

    detdet)('det

    1

    1111

    ikakoaa

    AaaAaaaaaaaA

    n

    jijkj

    n

    jijkj

    n

    jijkj

    n

    jijij

    n

    jijkjij

    =

    =+=+=+=

    =

    =

    =

    =

    =

  • 1:

    23

    : (*).

    bij=ai1aj1*+ai2aj2*+ . . . +ainajn* , 36 bii=A, bij=0 ij. A(A*)T A A(A*)T=AI, I A. (A*)TA=AI. 2.4.2:

    , . 2.4.5 A A0.

    : A0, . 2.4.5,

    A(A*)T=(A*)TA=AIn

    , A

    A , A_1 AA-1=A-1A=I.

    =

    =

    nnnn

    iniji

    nj

    nnjnn

    nj

    nj

    nnnn

    inii

    n

    T

    bbb

    bbb

    bbb

    aaa

    aaa

    aaa

    aaa

    aaa

    aaa

    AA

    ............

    ............

    ......

    ............

    ......

    ......

    ........

    ........

    ...

    *)(

    21

    1

    1111

    1

    2212

    1111

    21

    21

    11211

    IAAAA

    AAAAko

    TT

    T

    4400040004

    315222404

    212021

    211*)(*)(

    315222404

    *)(,4,212021

    211

    =

    =

    ==

    ==

    =

    IAAA

    AA

    A TT == )*)(1()*)(1(

    TAA

    A *)(11 =

  • 1:

    24

    2.4.4 AA-1=I AA-1=1

    A0. . k mxn. 2.4.3 k mxn

    k- k- , kmin{n,m}.

    2.4.4

    r(A).

    2.4.6 A n, A n. 2.4.7 mxn, r(A) min{n,m}. : 2.4.8 r(A-1)=r(A)=n. 2.4.9 r(AB) min{r(A),r(B)}.

    2.4.10 r(ATA)=r(AAT)=r(A).