document.write( "Question 1033413: Stacy has 30 meters of fencing that she wishes to use to enclose a rectangular garden. If all of the fencing is used, what is the maximum area of the garden, in square meters, that can be enclosed?\r
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document.write( "A)48.75
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document.write( "B)56.25
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document.write( "C)60.50
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document.write( "D)168.75 \n" );
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Algebra.Com's Answer #648031 by Boreal(15235)![]() ![]() You can put this solution on YOUR website! The maximum area for a rectangle is when it is a square. This can be proven a variety of ways, but I will use that. \n" ); document.write( "7.5 m on a side \n" ); document.write( "7.5^2=56.25 sq m. B\r \n" ); document.write( "\n" ); document.write( "Let x equal a side of a rectangle and y equal the other side \n" ); document.write( "P=2x+2y \n" ); document.write( "(P-2y)/2=x \n" ); document.write( "area ix xy=y(P-2y)/2=[Py-2y^2]/2 \n" ); document.write( "The maximum of this quadratic (which has a vertex at highest point, because the y^2 coefficient is negative is at (1/2)(P-4y). \n" ); document.write( "Set that equal to 0, multiply by 2 and move terms, and 4y must equal P. \n" ); document.write( "y=(1/4)P, and that is a square. \n" ); document.write( " \n" ); document.write( " |