document.write( "Question 581762: Suppose a farmer has 1000m of fencing to enclose a rectangular
\n" ); document.write( "field. What is the largest area that the farmer can enclose?
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Algebra.Com's Answer #371796 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
The Perimeter is:
\n" ); document.write( "\"+P+=+2W+%2B+2L+\"
\n" ); document.write( "\"+1000+=+2W+%2B+2L+\"
\n" ); document.write( "\"+500+=+W+%2B+L+\"
\n" ); document.write( "\"+L+=+500+-+W+\"
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\n" ); document.write( "The Area is:
\n" ); document.write( "\"+A+=+W%2AL+\"
\n" ); document.write( "\"+A+=+W%2A%28+500+-+W+%29+\"
\n" ); document.write( "\"+A+=+-W%5E2+%2B+500W+\"
\n" ); document.write( "--------------------
\n" ); document.write( "First of all, when the coefficient of the
\n" ); document.write( "squared term is negative, then there is a maximum
\n" ); document.write( "and not a minimum.
\n" ); document.write( "When the equation is in the form
\n" ); document.write( "\"+y+=+ax%5E2+%2B+ba+%2B+c+\", the max or min is
\n" ); document.write( "always at \"+x+=+-b%2F%282a%29+\", or, in this case,
\n" ); document.write( "\"+W%5Bmax%5D+=+-500%2F%282%2A%28-1%29%29+\"
\n" ); document.write( "\"+W%5Bmax%5D+=+250+\"
\n" ); document.write( "and I know that
\n" ); document.write( "\"+L+=+500+-+W+\"
\n" ); document.write( "\"+L%5Bmax%5D+=+500+-+250+\"
\n" ); document.write( "\"+L%5Bmax%5D+=+250+\"
\n" ); document.write( "The largest area that the farmer can enclose
\n" ); document.write( "is \"+250%2A250+\" = 62,500 ft2
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\n" ); document.write( "I can prove this by changing the dimensions
\n" ); document.write( "slightly, but still keeping the same Perimeter
\n" ); document.write( "\"+249%2A251+\" = 62,499 ft2
\n" ); document.write( "\"+248%2A252+\" = 62,496 ft2 ( even less )
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