document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=39285>Question 39285</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0321159349/algebrahomeworkh>College Algebra</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> Cost of material. A rectangular box with volume 320ft^3 is built with a square base and top. The cost is $1.50/ft^2 for the bottom, $2.50/ft^2 for the sides, and $1/ft^2 for the top. Let x=the length of the base, in feet.<BR>\n" );
document.write( "a) Express the cost of the box as a function of x.<BR>\n" );
document.write( "b) Find the domain of the function. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #24721 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=24721\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Cost of material. A rectangular box with volume 320ft^3 is built with a square base and top. The cost is $1.50/ft^2 for the bottom, $2.50/ft^2 for the sides, and $1/ft^2 for the top. Let x=the length of the base, in feet.<BR>\n" );
document.write( "a) Express the cost of the box as a function of x.<BR>\n" );
document.write( "Cost = cost of bottom + cost of top +4(cost of one side)<BR>\n" );
document.write( "cost of bottom= $1.5x^2<BR>\n" );
document.write( "cost of top =$1(x^2)<BR>\n" );
document.write( "To get cost of side need to know the height of a side, as follows.<BR>\n" );
document.write( "V=lwh<BR>\n" );
document.write( "320=x^2h<BR>\n" );
document.write( "h=320/x^2<BR>\n" );
document.write( "Area of one side is base(height)=x(320/x^2)=320/x<BR>\n" );
document.write( "Cost of 4 sides is 4($2.5)(320/x)=3200/x<BR>\n" );
document.write( "EQUATION:<BR>\n" );
document.write( "Cost =1.5x^2+x^2+3200/x<BR>\n" );
document.write( "   = 2.5x^2+3200/x\r<BR>\n" );
document.write( "\n" );
document.write( "b) Find the domain of the function.<BR>\n" );
document.write( "Domain of the FUNCTION is all Real numbers except x=0<BR>\n" );
document.write( "Domain of the function as a model of the problem is <BR>\n" );
document.write( "x>0<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );