document.write( "Question 309449: The volume of a cylindrical can is 500 cubed cm. the material used to make the top and bottom costs .o12 cent/squared cm, the material used for the sides costs .01 cent/ squared cm, and the seam joining the top and bottom to the sides costs .015 cent/cm. what size can would cost the least to produce?
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Algebra.Com's Answer #221325 by Fombitz(32388)\"\" \"About 
You can put this solution on YOUR website!
The can is a cylinder of radius R and length L.
\n" ); document.write( "\"V=pi%2AR%5E2%2AL=500\"
\n" ); document.write( "The total cost is the cost of the top and bottom plus the cost of the sidewall. The costs are based on total area.
\n" ); document.write( "The top and bottom are both circles of radius R.
\n" ); document.write( "\"+A=pi%2AR%5E2\"
\n" ); document.write( "The contribution to the total cost is,
\n" ); document.write( "\"+Ct%2BCb=2%2Api%2AR%5E2%2A0.012%0D%0ATHe+sidewall+is+a+rectangle+of+length+%7B%7B%7B2piR\" and width \"L\".
\n" ); document.write( "\"+A=2%2Api%2ARL\"
\n" ); document.write( "Its contribution to the total cost is,
\n" ); document.write( "\"+Cs=2%2Api%2ARL%2A0.01\"
\n" ); document.write( "The final contributor to cost is the seam which is length L.
\n" ); document.write( "Its contribution is
\n" ); document.write( "\"+Cx=L%2A0.015\"
\n" ); document.write( "The total cost equation is then
\n" ); document.write( "\"+Ctot=Ct%2BCb%2BCs%2BCx=0.024%2Api%2AR%5E2%2B0.02%2Api%2ARL%2B0.015L+\"
\n" ); document.write( "Using the volume equation you can get L as a function of R.
\n" ); document.write( "\"pi%2AR%5E2%2AL=500\"
\n" ); document.write( "\"R%5E2=500%2F%28pi%2AL%29\"
\n" ); document.write( "Now substitute into the cost equation,
\n" ); document.write( "\"+Ctot=0.024%2Api%2AR%5E2%2B0.02%2Api%2ARL%2B0.015L+\"
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\n" ); document.write( "\"+Ctot=12%2FL%2B0.7927%2Asqrt%28L%29%2B0.015L\"
\n" ); document.write( "Now you have total cost as the function of one variable.
\n" ); document.write( "To find the minimum cost, take the derivative and set it equal to zero.
\n" ); document.write( "\"dC%2Fdt=-12%2FL%5E2%2B%281%2F2%29%280.7927%29%2Fsqrt%28L%29%2B0.015=0\"
\n" ); document.write( "I solved this numerically in EXCEL and got \"highlight_green%28L=9.02%29\"
\n" ); document.write( "From that, then use the volume equation to find R.
\n" ); document.write( "\"R%5E2=500%2F%28pi%2AL%29\"
\n" ); document.write( "\"R%5E2=500%2F%28pi%2A9.02%29\"
\n" ); document.write( "\"highlight_green%28R=4.20%29\"
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