document.write( "Question 945997: A farmer wishes to put a fence around a rectangular field and then divide the field into three rectangular plots by placing two fences parallel to one of the sides. If the farmer can afford only 1000 yards of fencing, what dimensions will give the maximum rectangular area? \n" ); document.write( "
Algebra.Com's Answer #577077 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
Let \"+W+\" = the width of the field
\n" ); document.write( "Let \"+L+\" = the length of the field
\n" ); document.write( "Let \"+A+\" = the area of the field
\n" ); document.write( "The length of fencing needed is:
\n" ); document.write( "(1) \"+4W+%2B+2L+=+1000+\"
\n" ); document.write( "The area is:
\n" ); document.write( "(2) \"+A+=+W%2AL+\"
\n" ); document.write( "-----------------
\n" ); document.write( "(1) \"+2L+=+1000+-+4W+\"
\n" ); document.write( "(1) \"+L=+500+-+2W+\"
\n" ); document.write( "and
\n" ); document.write( "(2) \"+A+=+W%2A%28+500+-+2W+%29+\"
\n" ); document.write( "(2) \"+A+=+-2W%5E2+%2B+500W+\"
\n" ); document.write( "The maximum is at \"+W%5Bmax%5D+=++-b%2F%282a%29+\"
\n" ); document.write( "where
\n" ); document.write( "\"+a+=+-2+\"
\n" ); document.write( "\"+b+=+500+\"
\n" ); document.write( "\"+-b%2F%282a%29+=+-500+%2F+%28+2%2A%28-2%29%29+\"
\n" ); document.write( "\"+-b%2F%282a%29+=+125+\"
\n" ); document.write( "and
\n" ); document.write( "(1) \"+L=+500+-+2%2A125+\"
\n" ); document.write( "(1) \"+L+=+500+-+250+\"
\n" ); document.write( "(1) \"+L+=+250+\"
\n" ); document.write( "-----------------
\n" ); document.write( "The dimensions for maximum area are:
\n" ); document.write( "250 x 125
\n" ); document.write( "------------
\n" ); document.write( "check:
\n" ); document.write( "The length of fencing needed is:
\n" ); document.write( "(1) \"+4W+%2B+2L+=+1000+\"
\n" ); document.write( "(1) \"+4%2A125+%2B+2%2A250+=+1000+\"
\n" ); document.write( "(1) \"+500+%2B+500+=+1000+\"
\n" ); document.write( "OK
\n" ); document.write( "Here's the plot of the area:
\n" ); document.write( "\"+graph%28+400%2C+400%2C+-100%2C+300%2C+-4000%2C+35000%2C+-2x%5E2+%2B+500x+%29+\"
\n" ); document.write( "\"+250%2A125+=+31250+\"
\n" ); document.write( "\"+A%5Bmax%5D+=+31250+\"
\n" ); document.write( "at \"+W+=+125+\"
\n" ); document.write( "looks OK\r
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