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3 0 . Îá÷èñëèòè àëãåáðà¿÷í³ äîïîâíåííÿ åëåìåíò³â òðàíñïî-<br />
T<br />
A = A i = 1, n; j = 1, n ³ ñêëàñòè ³ç íèõ<br />
íîâàíî¿ ìàòðèö³ ij ji ( )<br />
ñîþçíó ìàòðèöþ A : a ( 1, ; 1, )<br />
T<br />
ij<br />
= Aij = Aji<br />
i = n j = n<br />
% % .<br />
4 0 . Êîæíèé åëåìåíò îòðèìàíî¿ ìàòðèö³ ðîçä³ëèòè íà<br />
âèçíà÷íèê äàíî¿ ìàòðèö³, òîáòî çàñòîñóâàòè ôîðìóëó äëÿ<br />
çíàõîäæåííÿ îáåðíåíî¿ ôóíêö³¿<br />
æA11 A12 ... A ö 1n<br />
1 1<br />
° °<br />
A21 A22 ... A<br />
-<br />
2n<br />
A = A,<br />
A<br />
=ç ç det A<br />
... ... ... ...<br />
. (2.5.2)<br />
èç<br />
An 1<br />
An2<br />
... A<br />
nnø÷<br />
5 0 . Ïåðåâ³ðèòè ïðàâèëüí³ñòü îá÷èñëåííÿ ó â³äïîâ³äíîñò³<br />
äî àëãîðèòìó 1 0 –4 0 . (Ïåâíà ð³÷, ï. 5 0 âèêîíóâàòè íåîáîâ’ÿçêîâî.<br />
Àëå äëÿ ãàðàíò³¿ â³í íå çàâàäèòü).<br />
2.5.3. Âëàñòèâîñò³ íåâèðîäæåíèõ ìàòðèöü<br />
¯õ ïîäàìî áåç äîâåäåííÿ.<br />
1. det À -1 ⋅ det À =1.<br />
2. (À -1 ) -1 = À.<br />
3. (ÀÂ) -1 = Â -1 À -1 .<br />
Ïðèêëàä 2.5.1. Çíàéòè ìàòðèöþ, ÿêà îáåðíåíà äî ìàòðèö³<br />
æ1 2 1ö<br />
- - A = 3 1 2<br />
.<br />
çè1 2 2ø<br />
÷<br />
1 -2 -1<br />
Ðîçâ’ÿçàííÿ. 1 0 . D= 3 1 2 = 1¹<br />
0.<br />
1 2 2<br />
2 0 . Òðàíñïîíóºìî ìàòðèöþ A ó â³äïîâ³äíîñò³ äî ïðàâèëà<br />
¿¿ óòâîðåííÿ.<br />
3 0 –4 0 . Îá÷èñëþºìî àëãåáðà¿÷í³ äîïîâíåííÿ òðàíñïîíîâàíî¿<br />
ìàòðèö³<br />
À 11 = –2, À 12 = –4, À 13 = 5, À 21 = 2, À 22 = 3, À 23 = –4, À 31 = –3,<br />
À 32 = –5, À 33 =7.<br />
Ïîñë³äîâíî çíàõîäèìî îáåðíåíó ìàòðèöþ<br />
æ 2 2 3ö æ 2 2 3ö<br />
- - - -<br />
° 1<br />
A=- 4 3 5 , A - 4 3 5<br />
- =- -<br />
.<br />
çè 5 -4 7 ÷ ø çè 5 -4 7ø<br />
÷<br />
Ïåðåâ³ðÿºìî: À ⋅ À -1 = Å.<br />
ÂÏÐÀÂÈ<br />
2.13. Íàéòè ìàòðèöþ AB, äå<br />
æ5 3 - 2ö<br />
æ1 2 3 5ö<br />
1 1 0 - A= ; 2 1 3 2<br />
B= -<br />
2 1 0<br />
ç<br />
4 2 3 - 4<br />
÷ .<br />
è ø<br />
çè4 - 2 2 ø÷ ÷<br />
2.14. ϳäïðèºìñòâî âèðîáëÿº ïðîäóêö³þ òðüîõ âèä³â ³<br />
âèêîðèñòîâóº ñèðîâèíó äâîõ òèï³â. Íîðìà âèòðàò ñèðîâèíè<br />
íà îäèíèöþ ïðîäóêö³¿ çàäàíî ìàòðèöåþ<br />
A<br />
æ1 2 3ö = ç çè3 4 5ø<br />
÷ .<br />
Âàðò³ñòü îäèíèö³ ñèðîâèíè êîæíîãî âèäó çàäàíî âåêòîðîì<br />
ö³í P = (20 30). ßê³ çàãàëüí³ âèòðàòè ï³äïðèºìñòâà íà<br />
âèðîáíèöòâî 1000 îäèíèöü ïðîäóêö³¿ ïåðøîãî âèäó, 2000<br />
îäèíèöü ïðîäóêö³¿ äðóãîãî âèäó ³ 1500 îäèíèöü òðåòüîãî<br />
âèäó?<br />
2.15. Íàéòè äîáóòîê ABC ìàòðèöü<br />
A<br />
æ1 2ö æ-7 4ö æ 9 10ö<br />
= , = , =<br />
çè3 4 ÷ ø B è ç 5 6 ÷ ø C èç-<br />
11 12ø<br />
÷ .<br />
2.16. Ïðèäóìàòè ³ ðîçâ’ÿçàòè âïðàâó, ÿêà àíàëîã³÷íà<br />
ïðèêëàäó 2.2.3.<br />
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