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äàòêîâ³é âàðòîñò³ ïðîäóêö³¿ çà ðàõóíîê çá³ëüøåííÿ ôîíä³â<br />

ï³äïðèºìñòâà íà îäíó îäèíèöþ (êóïèëè îäèí âåðñòàê).<br />

×àñòèííà ïîõ³äíà â³ä âèðîáíè÷î¿ ôóíêö³¿ z = f(x, y) ïî<br />

îáñÿãó òðóäîâèõ ðåñóðñ³â â òî÷ö³ M 0 (x 0 , y 0 ) íàáëèæåíî äîð³âíþº<br />

äîäàòêîâ³é âàðòîñò³ ïðîäóêö³¿, âèðîáëåíî¿ ùå îäíèì<br />

äîäàòêîâèì ðîá³òíèêîì.<br />

z′ x , y òà<br />

y<br />

Ââåäåí³ òóò ÷àñòèíí³ ïîõ³äí³ â òî÷ö³ x ( 0 0)<br />

( 0,<br />

0)<br />

z′ x y íàçèâàþòüñÿ â³äïîâ³äíî ãðàíè÷íîþ ïðîäóêòèâí³ñòþ<br />

òà ãðàíè÷íîþ ôîíäîâ³ääà÷åþ.<br />

×åðåç ò³æ ïðè÷èíè, ùî áóëè ïîäàí³ ðàí³øå, â åêîíîì³ö³<br />

(äèâ. ï. 7), ââîäÿòü òàêå âàæëèâå ïîíÿòòÿ, ÿê ÷àñòèííà åëàñòè÷í³ñòü.<br />

Äëÿ ðîçãëÿíóòî¿ âèðîáíè÷î¿ ôóíêö³¿ z = f(x, y)<br />

÷àñòèíí³ åëàñòè÷íîñò³ â òî÷ö³ M 0 (x 0 , y 0 ) ìàþòü âèãëÿä:<br />

z x<br />

E ( , ) 0<br />

x<br />

x y = z′<br />

( x , y ), (10.3.10)<br />

0 0 x 0 0<br />

z0<br />

z y<br />

E ( , ) 0<br />

y<br />

x y = z′<br />

( x , y ), (10.3.11)<br />

0 0 y 0 0<br />

z0<br />

äå z 0 = f(x 0 , y 0 ).<br />

Ïðèêëàä 10.3.2. Íåõàé âèðîáíèöòâî äåÿêîãî ï³äïðèºìñòâà<br />

õàðàêòåðèçóºòüñÿ âèðîáíè÷îþ ôóíêö³ºþ Êîááà – Äóãëàñà<br />

z = Ax α y β , α +β≤1, x — îáñÿã ôîíä³â, y — îáñÿã òðóäîâèõ ðåñóðñ³â<br />

(íàïðèêëàä, ê³ëüê³ñòü ðîá³òíèê³â).<br />

Òðåáà çíàéòè ãðàíè÷íó ïðîäóêòèâí³ñòü ïðàö³ òà ãðàíè÷íó<br />

ôîíäîâ³ääà÷ó ïðè x =25⋅ 10 8 , y = 1000.<br />

Ðîçâ’ÿçàííÿ<br />

α−1<br />

β<br />

1<br />

z′ = Aα⋅ x y , z′ = Aβ⋅ x α y<br />

β− ;<br />

x<br />

y<br />

( 8 ) ( 8 α−<br />

A ) 1<br />

β<br />

z′ 25 ⋅ 10 ,1000 = α⋅ 25 ⋅ 10 1000 ,<br />

x<br />

( ) A ( )<br />

8 8 α<br />

β− 1<br />

z′ 25 ⋅ 10 ,1000 = β⋅ 25 ⋅ 10 1000 .<br />

y<br />

Ïðèêëàä 10.3.3. Íåõàé ñïðàâäæóþòüñÿ óìîâè ïðèêëàäó<br />

10.3.2.<br />

Òðåáà âèçíà÷èòè ïàðàìåòðè A, α ³ β âèðîáíè÷î¿ ôóíêö³¿<br />

Êîááà – Äóãëàñà, ÿêùî â³äîìî, ùî äëÿ çá³ëüøåííÿ âèïóñêó<br />

ïðîäóêö³¿ íà 5% íåîáõ³äíî çá³ëüøèòè ôîíäè íà 10% àáî<br />

çá³ëüøèòè ÷èñåëüí³ñòü ðîá³òíèê³â íà 15%.  ìîìåíò äîñë³äæåííÿ<br />

îäèí ðîá³òíèê çà ì³ñÿöü âèðîáëÿº ïðîäóêö³þ íà<br />

100 000 ãðí., à âñüîãî ðîá³òíèê³â 1000.<br />

Ðîçâ’ÿçàííÿ. Çíàõîäèìî ñïî÷àòêó ÷àñòèíí³ åëàñòè÷íîñò³<br />

z<br />

x<br />

E ( 25 ⋅ 10 8 ,10<br />

3 ) = α− 1 β<br />

x<br />

A x y<br />

α β<br />

8 8<br />

Ax y x = 25 ⋅ 10 ⋅ α x = 25 ⋅10<br />

= α .<br />

3 3<br />

y = 10 y = 10<br />

5 1<br />

Ç ³íøîãî áîêó, ³ç óìîâ çàäà÷³ âèïëèâàº, ùî α= = .<br />

10 2<br />

z<br />

8 3 5 1<br />

Àíàëîã³÷íî ïîêàçóºòüñÿ, ùî Ey<br />

( 25⋅ 10 ,10 ) =β= = .<br />

15 3<br />

Òàêèì ÷èíîì, åëàñòè÷í³ñòü β âèïóñêó ïðîäóêö³¿ ïî òðóäó<br />

äîð³âíþº 1 3 , à åëàñòè÷í³ñòü α ïî ôîíäàõ äîð³âíþº 1 2 .<br />

Âðàõîâóþ÷è öåé ôàêò, âèðîáíè÷ó ôóíêö³þ Êîááà – Äóãëàñà<br />

çàïèñóºìî ó âèãëÿä³:<br />

1 1<br />

2 3<br />

.<br />

z = Ax y<br />

ϳäñòàâèìî ³íø³ äàíí³ çàäà÷³ ³ îòðèìàºìî ð³âí³ñòü<br />

1 1<br />

8 2 3<br />

4 5<br />

( ) ( )<br />

100000 ⋅ 1000 = A ⋅ 25 ⋅10 ⋅ 1000 = A⋅5 ⋅10 ⋅ 10 = A ⋅5 ⋅ 10 ,<br />

çâ³äêè, A = 200.<br />

Îòæå, îñòàòî÷íî ôóíêö³ÿ Êîááà – Äóãëàñà ìຠâèãëÿä<br />

1 1<br />

2 3<br />

z = 200x y .<br />

Çàóâàæåííÿ. Äëÿ çðó÷íîñò³ ïðè ðîçâ’ÿçóâàíí³ ïðèêëàäó<br />

ìè çàì³íèëè òðàäèö³éí³ çì³íí³ K, L ³ y íà x, y ³ z.<br />

364 365

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