document.write( "Question 1134762: A Norman window is constructed by adjoining a semicircle to the top of ab ordinary rectangular window. The perimeter of the window is 12 feet. The diameter of a circle and the length of a rectangle are x, the width is y.
\n" ); document.write( "1) Write the area A of the window as a function of x.
\n" ); document.write( "2) What dimensions will produce a window of maximum area?
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Algebra.Com's Answer #752244 by MathLover1(20850)\"\" \"About 
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given:
\n" ); document.write( " The perimeter of the window is \"12\" feet. The diameter of a circle and the length of a rectangle are \"x\" the width is \"y\".\r
\n" ); document.write( "\n" ); document.write( "1) Write the area \"A\" of the window as a function of \"x\".\r
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\n" ); document.write( "\n" ); document.write( "The perimeter is \"12\" ft.\r
\n" ); document.write( "\n" ); document.write( "\"P+=+2y+%2B+x+%2B1%2F2%282pi%2Ar%29+\"\r
\n" ); document.write( "\n" ); document.write( "\"P=+2y+%2B+x+%2B+pi%28x%2F2%29\"\r
\n" ); document.write( "\n" ); document.write( "\"P=+2y+%2B%281+%2Bpi%2F2%29x\" .......given \"P=+12\".\r
\n" ); document.write( "\n" ); document.write( "\"12=+2y+%2B%281+%2Bpi%2F2%29x\".....solve for \"y\"\r
\n" ); document.write( "\n" ); document.write( "\"2y+=12-%281+%2Bpi%2F2%29x\"\r
\n" ); document.write( "\n" ); document.write( "\"y+=6-%28%282+%2Bpi%29x%2F2%29%2F2\"\r
\n" ); document.write( "\n" ); document.write( "\"y+=6-%28%282+%2Bpi%29x%29%2F4\"\r
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\n" ); document.write( "\n" ); document.write( "We find an equation for maximum area.\r
\n" ); document.write( "\n" ); document.write( "\"A+=+xy+%2B%281%2F2%29pi%2Ar%5E2\" ......\"r=x%2F2\"\r
\n" ); document.write( "\n" ); document.write( "\"A+=+xy+%2B%281%2F2%29pi%2A%28x%2F2%29%5E2\"
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\n" ); document.write( "\"A+=+xy+%2B%281%2F2%29pi%2A%28x%5E2%2F4%29\"
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\n" ); document.write( "\"A+=+xy+%2B%281%2F8%29pi%2Ax%5E2\" \r
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\n" ); document.write( "\n" ); document.write( "Substitute in for \"y\". Now\r
\n" ); document.write( "\n" ); document.write( "\"A+=+x%286-%28%282+%2Bpi%29x%29%2F4%29+%2B%281%2F8%29pi%2Ax%5E2+\"\r
\n" ); document.write( "\n" ); document.write( "\"A+=+6x-%281%2F4%29%282+%2Bpi%29x%5E2+%2B%281%2F8%29pi%2Ax%5E2+\"\r
\n" ); document.write( "\n" ); document.write( "\"A+=+-%28pi%2Ax%5E2%29%2F8+-+x%5E2%2F2+%2B+6x\"\r
\n" ); document.write( "\n" ); document.write( "\"A+=+-%281%2F8%29+%284+%2B+pi%29+x%5E2%2B+6x\"->the area \"A\" of the window as a function of \"x\"\r
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\n" ); document.write( "\n" ); document.write( "2) What dimensions will produce a window of maximum area?\r
\n" ); document.write( "\n" ); document.write( "Next compute \"dA%2Fdx\". Set it equal to zero and solve for \"x\".\r
\n" ); document.write( "\n" ); document.write( "\"dA%2Fdx+=+2%28-1%2F8%29%284+%2B+pi%29x%2B6\"\r
\n" ); document.write( "\n" ); document.write( "\"dA%2Fdx+=+-%281%2F4%29+%284+%2B+pi%29x%2B6\"\r
\n" ); document.write( "\n" ); document.write( "set =\"+0\".\r
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\n" ); document.write( "\n" ); document.write( "\"-%281%2F4%29+%284+%2B+pi%29x%2B6=0\"\r
\n" ); document.write( "\n" ); document.write( "\"%281%2F4%29+%284+%2B+pi%29x=6\"\r
\n" ); document.write( "\n" ); document.write( "\"+%284+%2B+pi%29x=6%2F%281%2F4%29\"\r
\n" ); document.write( "\n" ); document.write( " \"%284+%2B+pi%29x=24\"\r
\n" ); document.write( "\n" ); document.write( "\"x=24%2F%284+%2B+pi%29\"
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\n" ); document.write( "\"x=24%2F%284+%2B+3.14%29+\"\r
\n" ); document.write( "\n" ); document.write( "\"x=24%2F7.14\"\r
\n" ); document.write( "\n" ); document.write( "\"x\"\"3.35ft\"\r
\n" ); document.write( "\n" ); document.write( "then \"r=3.35ft%2F2=1.675\"\r
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\n" ); document.write( "\n" ); document.write( "Next find \"y\".\r
\n" ); document.write( "\n" ); document.write( "\"y+=%286-%282+%2Bpi%29x%29%2F4\"\r
\n" ); document.write( "\n" ); document.write( "\"y+=%286-%282+%2B3.14%293.35%29%2F4\"\r
\n" ); document.write( "\n" ); document.write( "\"y+=%286-5.14%2A3.35%29%2F4\"\r
\n" ); document.write( "\n" ); document.write( "\"y+=6-%285.14%2A3.35%29%2F4\"\r
\n" ); document.write( "\n" ); document.write( "\"y\"\"1.7ft\"\r
\n" ); document.write( "\n" ); document.write( "dimensions that will produce a window of maximum area are:\r
\n" ); document.write( "\n" ); document.write( "\"x\"\"3.35ft\"\r
\n" ); document.write( "\n" ); document.write( "\"r\"\"1.675\"\r
\n" ); document.write( "\n" ); document.write( "\"y\"\"1.7ft\"\r
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\n" ); document.write( "\n" ); document.write( "check the perimeter first then see what would be maximum area\r
\n" ); document.write( "\n" ); document.write( "\"12=+2y+%2B%281+%2Bpi%2F2%29x\"\r
\n" ); document.write( "\n" ); document.write( "\"12=+2%2A1.7+%2B%281+%2B3.14%2F2%293.35\"\r
\n" ); document.write( "\n" ); document.write( "\"12=+2%2A1.7+%2B%28%282+%2B3.14%29%2F2%293.35\"\r
\n" ); document.write( "\n" ); document.write( "\"12=+2%2A1.7+%2B%285.14%2A3.35%29%2F2\"\r
\n" ); document.write( "\n" ); document.write( "\"12=+3.4+%2B8.6095\"\r
\n" ); document.write( "\n" ); document.write( "\"12=+12.0095\"\r
\n" ); document.write( "\n" ); document.write( "\"12=+12\"-> true\r
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\n" ); document.write( "\n" ); document.write( "now find maximum area\r
\n" ); document.write( "\n" ); document.write( "\"A+=+xy+%2B%281%2F8%29pi%2Ax%5E2+\"\r
\n" ); document.write( "\n" ); document.write( "\"A+=+3.35%2A1.7+%2B%281%2F8%293.14%2A%283.35%29%5E2\"
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\n" ); document.write( "\"A+=+5.695+%2B%281%2F8%293.14%2A11.2225\"\r
\n" ); document.write( "\n" ); document.write( "\"A+=+5.695+%2B4.40483125\"\r
\n" ); document.write( "\n" ); document.write( "\"A+=+5.695+%2B4.40483125\"\r
\n" ); document.write( "\n" ); document.write( "\"A+=10.0998\"\r
\n" ); document.write( "\n" ); document.write( "\"A+\"\"10ft%5E2\"\r
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