optimization - area and cost

Tascja

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Mar 4, 2006
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okay here is a problem that i have no clue what exactly im supposed to be doing.. ive tried it so many ways and none of them turn out.. so here it is:

A rectangular piece of land is to be fenced in using two kinds of fencing. Two opposite sides will be fenced using standard fencing that costs $6/m, while the other two sides will require heavy-duty fencing that costs $9/m. What are the dimensions of the rectangular lot of greatest area that can be fenced in for a cost of $9000?

if you could include all the steps that would be GREATLY appreciated. Thanx!!
 
Tascja said:
okay here is a problem that i have no clue what exactly im supposed to be doing.. ive tried it so many ways and none of them turn out.. so here it is:

A rectangular piece of land is to be fenced in using two kinds of fencing. Two opposite sides will be fenced using standard fencing that costs $6/m, while the other two sides will require heavy-duty fencing that costs $9/m. What are the dimensions of the rectangular lot of greatest area that can be fenced in for a cost of $9000?

if you could include all the steps that would be GREATLY appreciated. Thanx!!

Sorry I am really tired, some im gonna post a brief overview of what you need to do. Hopefully someone will post more tomorrow.

Step1. create a formula (using area of rec.)
Step2. take derivative of said formula
Step3. Find your critical numbers
Step4. Figure out your Max on your interval.
 
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