document.write( "Question 1013245: the premiter of rectangle ABCD is 20 inches. find the least value, in inches, of diagonal AC. answers must be in exact form. \n" ); document.write( "
Algebra.Com's Answer #629461 by stanbon(75887)\"\" \"About 
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the perimiter of rectangle ABCD is 20 inches. find the least value, in inches, of diagonal AC. answers must be in exact form.
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\n" ); document.write( "P = 2(L + W)
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\n" ); document.write( "20 = 2(L+W)
\n" ); document.write( "L+W = 10
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\n" ); document.write( "Diam = sqrt[L^2 + W^2)
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\n" ); document.write( "Substitute for \"L\" to get:
\n" ); document.write( "D = sqrt[(10-W)^2 + W^2]
\n" ); document.write( "D = sqrt[2W^2 - 20W + 100]
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\n" ); document.write( "Take the derivative to get:
\n" ); document.write( "D' = (1/2)(4W-20)/sqrt(2W^2-20W+100)
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\n" ); document.write( "Solve:: 2W-10 = 0
\n" ); document.write( "W = 5
\n" ); document.write( "Then L = 5
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\n" ); document.write( "Ans: D = sqrt[5^2 + 5^2] = sqrt(2*25) = 5sqrt(2)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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