document.write( "Question 171903This question is from textbook Algebra & Trigonometry
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document.write( ": This problem is in the review section about the farmer and fencing.\r
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document.write( "A farmer with 10,000 meters of fencing wants to enclose a rectangular field and then divide it into two plots with a fence parallel to one of the sided. What is the largest area that can be enclosed?\r
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document.write( "I really have no clue even where to start by solving this problem, I have searched it and found that we need to maximize the area by using a formula that looks something like(2wx2L=?) but after applying it to my problem I came up with this formula (2Lx3W=10,000. I have no clue if I am even going in the right direction. I used the two lengths because we have two long sides, and 3 widths because there is also the dividing line of fence that has to be accounted for. Any help is appreciated.\r
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document.write( "Thanks,
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document.write( "Kim \n" );
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Algebra.Com's Answer #127006 by Alan3354(69443)![]() ![]() You can put this solution on YOUR website! This problem is in the review section about the farmer and fencing. \n" ); document.write( "A farmer with 10,000 meters of fencing wants to enclose a rectangular field and then divide it into two plots with a fence parallel to one of the sides. What is the largest area that can be enclosed? \n" ); document.write( "--------------------- \n" ); document.write( "Farmers always want to complicate things, it seems. \n" ); document.write( "Call W the Width and L the Length with 3 pieces. \n" ); document.write( "The total length will be 2W + 3L \n" ); document.write( "The Area is L*W \n" ); document.write( "so, \n" ); document.write( "A = L*W \n" ); document.write( "2W+3L = 10000 \n" ); document.write( "Solve for L \n" ); document.write( "3L = 10000-2W \n" ); document.write( "L = (10000-2W)/3 \n" ); document.write( "sub for L into the first eqn \n" ); document.write( "A = L*W \n" ); document.write( "A = W*(10000-2W)/3 \n" ); document.write( "A = (10000W - 2W^2)/3 \n" ); document.write( "Now, to find the max, set the 1st derivative = 0. I don't know if you know what that means, but... \n" ); document.write( "dA/dW = 10000/3 - 4W/3 = 0 \n" ); document.write( "10000 - 4W = 0 \n" ); document.write( "W = 2500 meters \n" ); document.write( "------------- \n" ); document.write( "Solve for L \n" ); document.write( "2W+3L = 10000 \n" ); document.write( "5000 + 3L = 10000 \n" ); document.write( "3L = 5000 \n" ); document.write( "L = 1667 meters \n" ); document.write( "Area = 2500*5000/3 =~ 4,166,666.67 sq meters \n" ); document.write( "----------------- \n" ); document.write( "Making just a square would have enclosed 5000*5000 = 25,000,000 sq meters, the max area of a rectangle with a given perimeter. \n" ); document.write( " \n" ); document.write( " |