document.write( "Question 86483: An open-top box is to be constructed from a 4 foot by 6 foot rectangular cardboard by cutting out equal squares at each corner and folding up the flaps. Let x denote the length of each side of the square to be cut out.
\n" ); document.write( "a) Find the function V that represents the volume of the box in terms of x.
\n" ); document.write( "Answer: \r
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\n" ); document.write( "\n" ); document.write( "b) Graph this function and show the graph over the valid range of the variable x..
\n" ); document.write( "Show Graph here.\r
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\n" ); document.write( "\n" ); document.write( "c) Using the graph, what is the value of x that will produce the maximum volume?
\n" ); document.write( "Answer.
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Algebra.Com's Answer #62592 by Nate(3500)\"\" \"About 
You can put this solution on YOUR website!
An open-top box is to be constructed from a 4 foot by 6 foot rectangular cardboard by cutting out equal squares at each corner and folding up the flaps. Let x denote the length of each side of the square to be cut out.
\n" ); document.write( "a) Find the function V that represents the volume of the box in terms of x.
\n" ); document.write( "Answer:
\n" ); document.write( "Drawing a picture would be extremely helpful.
\n" ); document.write( "1. Draw a 4 by 6 foot rectangle
\n" ); document.write( "2. Make boxes at each of the four corners with sides x feet
\n" ); document.write( "Length: 6 - 2x
\n" ); document.write( "Width: 4 - 2x
\n" ); document.write( "Height: x
\n" ); document.write( "V = product of all sides
\n" ); document.write( "V = (6 - 2x)(4 - 2x)(x)
\n" ); document.write( "V = 4(3 - x)(2 - x)(x)
\n" ); document.write( "V = 4(6 - 5x + x^2)(x)
\n" ); document.write( "V = 4(6x - 5x^2 + x^3)
\n" ); document.write( "V = 24x - 20x^2 + 4x^3\r
\n" ); document.write( "\n" ); document.write( "b) Graph this function and show the graph over the valid range of the variable x..
\n" ); document.write( "Show Graph here. \r
\n" ); document.write( "\n" ); document.write( "\"graph%28300%2C300%2C-1%2C4%2C-10%2C10%2C24x+-+20x%5E2+%2B+4x%5E3%29\"\r
\n" ); document.write( "\n" ); document.write( "c) Using the graph, what is the value of x that will produce the maximum volume?
\n" ); document.write( "Answer.
\n" ); document.write( "Approx. when x = 1
\n" ); document.write( "~~~~
\n" ); document.write( "V(x) = 24x - 20x^2 + 4x^3
\n" ); document.write( "V'(x) = 24 - 40x + 12x^2
\n" ); document.write( "0 = 6 - 10x + 3x^2
\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"
\n" ); document.write( "\"x+=+%2810+%2B-+sqrt%28+100+-+72+%29%29%2F%286%29+\"
\n" ); document.write( "\"x+=+%2810+%2B-+sqrt%28+28+%29%29%2F%286%29+\"
\n" ); document.write( "\"x+=+%2810+%2B-+2%2Asqrt%28+7+%29%29%2F%286%29+\"
\n" ); document.write( "\"x+=+%285+%2B-+sqrt%28+7+%29%29%2F%283%29+\"
\n" ); document.write( "~
\n" ); document.write( "Exact: \"x+=+%285+-+sqrt%287%29%29%2F3\"
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