document.write( "Question 913117: I'm not sure where to begin on this. I'm in Algebra II, but I feel like this is more of a pre-calc question. Any ideas? United Parcel Service has contracted you to design a closed box with a square base that
\n" ); document.write( "has a volume of 10,000 cubic inches. Initially they would like to know the dimensions of such a
\n" ); document.write( "box with minimum surface area. They are considering creating the box with a reinforced bottom.
\n" ); document.write( "The box would be made out of a cardboard material costing 1cent per square inch to build the walls
\n" ); document.write( "and top, however the bottom would be constructed with stronger material, costing 2cents per square
\n" ); document.write( "inch to build. How do the dimensions of the box having the minimum surface area compare to the
\n" ); document.write( "dimensions of the reinforced box which costs the least?
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Algebra.Com's Answer #554318 by josgarithmetic(39616)\"\" \"About 
You can put this solution on YOUR website!
The beginning for both of the functions first attends volume.\r
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\n" ); document.write( "\n" ); document.write( "Bottom is a square shape, so if x is the sidelength for the bottom (as well as top), and if y is height of box, then
\n" ); document.write( "\"10000=yx%5E2\"
\n" ); document.write( "and from it, \"y=10000%2Fx%5E2\".\r
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\n" ); document.write( "\n" ); document.write( "TOTAL SURFACE AREA\r
\n" ); document.write( "\n" ); document.write( "Let A be variable for total surface area, to be formed into a function of x.
\n" ); document.write( "\"A=2x%5E2%2B4xy\"
\n" ); document.write( "\"A=2x%5E2%2B4x%2810000%2Fx%5E2%29\"
\n" ); document.write( "\"highlight_green%28A=2x%5E2%2B40000%2Fx%29\" which you might possibly want as a single numerator expression and a single denominator expression.\r
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\n" ); document.write( "\n" ); document.write( "COST FUNCTION\r
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\n" ); document.write( "\n" ); document.write( "1 cent per sq in. for walls and top; 2 cents per sq. in. for bottom.
\n" ); document.write( "Let C be the cost for the box.\r
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\n" ); document.write( "\n" ); document.write( "\"C=%28x%5E2%29%282%29%2B%28x%5E2%29%281%29%2B4xy%2A1\"
\n" ); document.write( "\"2x%5E2%2Bx%5E2%2B4xy\"
\n" ); document.write( "\"3x%5E2%2B4x%2810000%2Fx%5E2%29\"
\n" ); document.write( "\"highlight_green%28C=3x%5E2%2B40000%2Fx%29\"\r
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\n" ); document.write( "\n" ); document.write( "The form of the area function and the cost function are the same. Both are rational functions. They show the same format.\r
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\n" ); document.write( "\n" ); document.write( "The question to minimize and then compare the dimensions of these two functions seems outside of and beyond Algebra II; but might be used in College Algebra, but more likely fit in Calculus 1. Very likely most Algebra II students are allowed, encourage, even TAUGHT TO USE a graphing calculator, so if this is something you know how to use, you can find useful results. Decide on the x value or pick what seems to correspond to each minimum, and use the value to evaluate y.\r
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\n" ); document.write( "\n" ); document.write( "...
\n" ); document.write( "AREA
\n" ); document.write( "\"graph%28350%2C350%2C-10%2C35%2C-150%2C5000%2C2x%5E2%2B40000%2Fx%29\"\r
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\n" ); document.write( "\n" ); document.write( "COST
\n" ); document.write( "\"graph%28350%2C350%2C-10%2C35%2C-150%2C5000%2C3x%5E2%2B40000%2Fx%29\"
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