document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1104503>Question 1104503</A>: <I><SPAN STYLE=\"word-break: break-all;\"> what are the dimension of the largest rectangular field that can be enclosed with 60 meter of wire </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #719261 by </B><A HREF=/tutors/aboutme.mpl?userid=math_helper><B>math_helper(2461)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=math_helper><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=math_helper><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=719261\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "Let the dimensions be L, W, and the area A.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+L+=+%2860-2W%29%2F2+=+30+-+W+ ALIGN=MIDDLE  ALT=\"+L+=+%2860-2W%29%2F2+=+30+-+W+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+A+=+LW+=+%2830-W%29W++=+30W-+W%5E2+ ALIGN=MIDDLE  ALT=\"+A+=+LW+=+%2830-W%29W++=+30W-+W%5E2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Take the derivative of A with respect to W:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+dA%2FdW+=+30-2W+ ALIGN=MIDDLE  ALT=\"+dA%2FdW+=+30-2W+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Set it to zero:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=++++30-2W+=+0++ ALIGN=MIDDLE  ALT=\"++++30-2W+=+0++\"   DISABLED_style= \"max-width:90%; height:auto;\" > —>  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+W=15m+ ALIGN=MIDDLE  ALT=\"+W=15m+\"   DISABLED_style= \"max-width:90%; height:auto;\" > —> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+L=15m+ ALIGN=MIDDLE  ALT=\"+L=15m+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "To show that's a max, note<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d%5E2A%2FdW%5E2+=+-2+ ALIGN=MIDDLE  ALT=\"+d%5E2A%2FdW%5E2+=+-2+\"   DISABLED_style= \"max-width:90%; height:auto;\" >   which indicates the curve is concave down (hence max at W=L=15)\r<BR>\n" );
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document.write( "—<BR>\n" );
document.write( "Ans:  The dimensions of the largest rectangle is  15m x 15m<BR>\n" );
document.write( "( Notice how it is a square that maximizes the area )<BR>\n" );
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