document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=830403>Question 830403</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 1) A rectangular enclosure,subdivided into 3 congruent pens,is to be made using a barn as one side and 120 meters of fencing for the rest of the enclosure.FInd the value of x that gives the maximum area for the enclosure.<BR>\n" );
document.write( "-Answer is 15,but I don't know how to get the answer.\r<BR>\n" );
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document.write( "2)The water in a cylindrical tank 4 ft in diameter empties through a hole in the bottom.Assuming that the water has a depth of 16ft at time t=0 and empties at the rate of 5 ft^3/s,express the depth of the water as a function of time.<BR>\n" );
document.write( "-Answer is d(t)=16-(5/4pi)t<BR>\n" );
document.write( "Don't know how to solve.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #500599 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=500599\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 1) A rectangular enclosure,subdivided into 3 congruent pens,is to be made using a barn as one side and 120 meters of fencing for the rest of the enclosure.FInd the value of x that gives the maximum area for the enclosure.<BR>\n" );
document.write( "-Answer is 15,but I don't know how to get the answer.<BR>\n" );
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document.write( "Draw the picture.<BR>\n" );
document.write( "You have 4 fences (perpendicular to the barn) that are x meters long.<BR>\n" );
document.write( "You have 1 fence (parallel to the barn) that is 120-4x meters long.<BR>\n" );
document.write( "Area = x(120-4x) = 120x-4x^2 sq meters<BR>\n" );
document.write( "----<BR>\n" );
document.write( "Maximum Area occurs when x = -b/(2a) = -120/(-8) = 15 meters<BR>\n" );
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document.write( "  <BR>\n" );
document.write( "2)The water in a cylindrical tank 4 ft in diameter empties through a hole in the bottom.Assuming that the water has a depth of 16ft at time t=0 and empties at the rate of 5 ft^3/s,express the depth of the water as a function of time.<BR>\n" );
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document.write( "Volume of water = pi*r^2*h = pi*4*16 = 64pi ft^3 ; depth = 16 ft<BR>\n" );
document.write( "Volume = 0 after 64pi/5 = 12.8pi seconds ; depth = 0 ft<BR>\n" );
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document.write( "You have 2 points (0,16) and (12 4/5,0) relating time to depth.<BR>\n" );
document.write( "slope = (16-0)/(0-12.8) = -1.25 <BR>\n" );
document.write( "d(t) = 16 - (5/4)t\r<BR>\n" );
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document.write( "===========<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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