document.write( "Question 310895: how do you find the dimensions of a rectangle with the smallest perimeter and an area of 120000 inches? \n" ); document.write( "
Algebra.Com's Answer #222429 by Fombitz(32388)\"\" \"About 
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The area of a rectangle is,
\n" ); document.write( "\"A=L%2AW=120000\"
\n" ); document.write( "\"L=120000%2FW\"
\n" ); document.write( "The perimeter of a rectangle is,
\n" ); document.write( "\"P=2%2A%28L%2BW%29\"
\n" ); document.write( "Substituting,
\n" ); document.write( "\"P=2%2A%28120000%2FW%2BW%29\"
\n" ); document.write( "Now P is a function of W only.
\n" ); document.write( "To minimize P, find the derivative wrt W and set it equal to zero.
\n" ); document.write( "\"dP%2FdW=2%2A%28-120000%2FW%5E2%2B1%29=0\"
\n" ); document.write( "\"120000%2FW%5E2=1\"
\n" ); document.write( "\"W%5E2=120000\"
\n" ); document.write( "\"W=sqrt%28120000%29\"
\n" ); document.write( "From the area equation above,
\n" ); document.write( "\"L=120000%2FW=120000%2Fsqrt%28120000%29=sqrt%28120000%29\"
\n" ); document.write( "The rectangle with the smallest perimeter and area of 120000 sq. in. is a square with sides of \"sqrt%28120000%29\" in.
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