06.03.2015 Views

ЛЕКЦІЇ ² ВПРАВИ

ЛЕКЦІЇ ² ВПРАВИ

ЛЕКЦІЇ ² ВПРАВИ

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Ïðèêëàä 2.2.2. Çíàéòè äîáóòîê ìàòðèöü<br />

123<br />

æ10ö æ ö A= i B 0 5<br />

=<br />

ç 456<br />

÷<br />

è ø .<br />

çè70ø<br />

÷<br />

Ðîçâ’ÿçàííÿ. Ö³ ìàòðèö³ òàêîæ ïîãîäæåí³ (ê³ëüê³ñòü<br />

ñòîâïö³â ìàòðèö³ A äîð³âíþº 3, à ê³ëüê³ñòü ðÿäê³â ìàòðèö³ B<br />

òàêîæ äîð³âíþº 3). Çà îçíà÷åííÿì äîáóòêó ìàòðèöü ìàºìî:<br />

æ10ö æ1 2 3ö æ1× 1+ 2× 0+ 3× 7 1× 0+ 2× 5+ 3×<br />

0ö æ22 10ö<br />

AB × = 05 × = =<br />

.<br />

ç 456 è ÷ ø ç41 × + 50 × + 67 × 40 × + 55 × + 60 ×<br />

÷ ç46 25<br />

è ø è ÷ ø<br />

çè70<br />

÷ ø<br />

Ïðèêëàä 2.2.3. ϳäðÿäíèê-áóä³âåëüíèê óêëàâ äîãîâ³ð íà<br />

áóä³âíèöòâî òàêèõ ñïîðóä: 3 øêîëè, 5 äèòÿ÷èõ ñàäê³â,<br />

9 æèòëîâèõ áóäèíê³â. Ìàòåð³àëàìè äëÿ áóä³âíèöòâà º ñòàëü,<br />

ë³ñ, ñêëî, öåãëà. ʳëüê³ñòü ñèðîâèíè, à òàêîæ ðîáî÷î¿ ñèëè<br />

íà êîæíèé âèä ñïîðóäè â äåÿêèõ óìîâíèõ îäèíèöÿõ âèçíà-<br />

÷àºòüñÿ ìàòðèöåþ<br />

⎛10 17 8 5 11⎞<br />

⎜<br />

⎟<br />

A = 7 12 4 3 8<br />

.<br />

⎜5 15 10 4 9⎟<br />

⎝<br />

⎠<br />

Òóò à 11 =10, à 21 =7, à 31 =5 â³äïîâ³äíî îçíà÷àº, ùî íà ñïîðóäó<br />

øêîëè, äèòÿ÷îãî ñàäêà, æèòëîâîãî áóäèíêó âèêîðèñòîâóºòüñÿ<br />

10, 7, 5 îäèíèöü ñòàë³ â³äïîâ³äíî; à 12 =17, à 22 =12, à 32 =15<br />

îçíà÷àº, ùî íà ñïîðóäó øêîëè, äèòÿ÷îãî ñàäêà, æèòëîâîãî<br />

áóäèíêó âèêîðèñòîâóºòüñÿ 17, 12, 15 îäèíèöü ë³ñó â³äïîâ³äíî;<br />

à 13 =8, à 23 =4, à 33 =10 îçíà÷àº, ùî íà ñïîðóäó øêîëè, äèòÿ-<br />

÷îãî ñàäêà, æèòëîâîãî áóäèíêó âèêîðèñòîâóºòüñÿ 8, 4, 10<br />

îäèíèöü ñêëà â³äïîâ³äíî; à 14 =5, à 24 =3, à 34 =4 îçíà÷àº, ùî íà<br />

ñïîðóäó øêîëè, äèòÿ÷îãî ñàäêà, æèòëîâîãî áóäèíêó âèêîðèñòîâóºòüñÿ<br />

5, 3, 4 îäèíèöü öåãëè â³äïîâ³äíî; à 15 =11, à 25 =8,<br />

à 35 =9 îçíà÷àº, ùî íà ñïîðóäó øêîëè, äèòÿ÷îãî ñàäêà, æèòëîâîãî<br />

áóäèíêó âèêîðèñòîâóºòüñÿ 11, 8, 9 îäèíèöü ðîáî÷î¿<br />

ñèëè â³äïîâ³äíî.<br />

Îäèíèöÿ ñòàë³ êîøòóº 120 ãðí., îäèíèöÿ ë³ñó — 70 ãðí.,<br />

îäèíèöÿ ñêëà — 50 ãðí., îäèíèöÿ öåãëè — 40 ãðí., îäèíèöÿ<br />

ðîáî÷î¿ ñèëè — 100 ãðí.<br />

Çàóâàæèìî, ùî âñ³ öèôðè, ÿê³ ô³ãóðóþòü â çàäà÷³, —<br />

óìîâí³ ³ íå â³äïîâ³äàþòü ä³éñíèì äàíèì.<br />

Òðåáà âèçíà÷èòè: 1. Çàãàëüíó ê³ëüê³ñòü íåîáõ³äíèõ ìàòåð³àë³â<br />

íà áóä³âíèöòâî ñïîðóä. 2. Âàðò³ñòü ìàòåð³àë³â ³ ðîáî-<br />

÷î¿ ñèëè äëÿ êîæíîãî âèäó ñïîðóä. 3. Çàãàëüíó âàðò³ñòü<br />

ìàòåð³àë³â ³ ðîáî÷î¿ ñèëè.<br />

Ðîçâ’ÿçàííÿ. 1. Äîãîâ³ð, ÿêèé ï³äðÿäíèê óêëàâ íà<br />

áóä³âíèöòâî ñïîðóä, çîáðàçèìî ó âèãëÿä³ âåêòîðà-ðÿäêà<br />

 = (3 5 9). Ùîá óçíàòè ê³ëüê³ñòü íåîáõ³äíèõ ìàòåð³àë³â ³<br />

îäèíèöü ðîáî÷î¿ ñèëè, òðåáà ïåðåìíîæèòè ìàòðèö³ À òà  ³<br />

çíàéòè äîáóòîê B ⋅ A ó âêàçàíîìó ïîðÿäêó. Öåé äîáóòîê ìàº<br />

ñåíñ, òîìó ùî â ìàòðèö³ B òðè ñòîâïö³, à â ìàòðèö³ À —<br />

ñò³ëüêè æ ðÿäê³â.  ðåçóëüòàò³ òàêîãî ïåðåìíîæåííÿ ìàºìî:<br />

ÂÀ = (110 246 134 66 154).<br />

Îòæå, ï³äðÿäíèê ïîâèíåí ïðèäáàòè ñòàë³ 110 îäèíèöü,<br />

ë³ñó 246 îäèíèöü, ñêëà 134 îäèíèö³, öåãëè 66 îäèíèöü òà<br />

154 îäèíèö³ ðîáî÷î¿ ñèëè.<br />

2. Ùîá óçíàòè âàðò³ñòü ìàòåð³àë³â òà ðîáî÷î¿ ñèëè ââåäåìî<br />

â ðîçãëÿä âåêòîð ö³í, ÿêèé äëÿ çðó÷íîñò³ ïîçíà÷èìî<br />

ÿê âåêòîð-ñòîâïåöü<br />

⎛120⎞<br />

⎜ ⎟<br />

⎜<br />

70<br />

⎟<br />

P = ⎜50<br />

⎟<br />

⎜ ⎟<br />

40<br />

.<br />

⎜ ⎟<br />

⎜100⎟<br />

⎝ ⎠<br />

Ïîìíîæèìî òåïåð ñïðàâà ìàòðèöþ À íà âåêòîð-ñòîâïåöü<br />

Ð. Â ðåçóëüòàò³ ìàòèìåìî<br />

⎛4090⎞<br />

⎜ ⎟<br />

AP = 2800<br />

.<br />

⎜3210⎟<br />

⎝ ⎠<br />

48 49

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!