求救!! pure/applied math

詩

2010-08-19 6:23 am

A truck is to travel 1000 kilometres at a constant speed of v km/h, the truck consumes fuel at the rate of :
[ 6+ v^2/50 ] litres per hour
The truck company pays $1.50 litre for fuel and pay each of two drivers $20 per hourwhile the truck is travelling. Let the total cost of fuel and the drivers' wages for the trip be C dollars. The truck must take no longer than 12 hours to complete the trip, and speed limits require that v <&= 100. At what speed v should the truck travel to minimise the cost C?

how to find the answer?
please tell me:)

更新1:

but the answer of v is 250/3 how to get it?

回答 (1)

STEVIE-G™

2010-08-19 8:27 am

✔ 最佳答案

As follows:

圖片參考：http://i707.photobucket.com/albums/ww74/stevieg90/03-104.jpg

2010-08-19 19:33:43 補充：
O....okok....Let me check it~

2010-08-19 20:41:04 補充：
The updated version has been uploaded, you can check it.

參考: http://i707.photobucket.com/albums/ww74/stevieg90/03-104.jpg

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