document.write( "Question 86386: Alan is building a garden shaped like a rectangle with a semicircle attached to one short side. If he has 70 feet of fencing to go around it, what dimensions will give him the maximum area in the garden?\r
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document.write( "I know that eventually you may have to use the X=b/2a formula
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Algebra.Com's Answer #62504 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! Alan is building a garden shaped like a rectangle with a semicircle attached to one short side. If he has 70 feet of fencing to go around it, what dimensions will give him the maximum area in the garden? \n" ); document.write( "---------------- \n" ); document.write( "Draw the picture. \n" ); document.write( "Let the shorter side be \"x\" \n" ); document.write( "Perimeter of the semi-circle is (pi)x \n" ); document.write( "Twice the Length of the longer side is [70-(pi)x -x] \n" ); document.write( "Length = [70-(1+pi)x]/2 \n" ); document.write( "Total area = area of rectangle + area of the semi-circle. \n" ); document.write( "Total area = x[[70-(1+pi)x]/2] + [(pi)(x/2)^2]/2 \n" ); document.write( "2Total area = 70x -(1+pi)x^2 + [(pi)(x^2/4)] \n" ); document.write( "2Total area = 70x +[(pi/4)-(1+pi)]x^2 \n" ); document.write( "2Total area = 70x - [3.3562]x^2 \n" ); document.write( "Total area = 35x - 1.6781x^2 \n" ); document.write( "------------- \n" ); document.write( "Max occurs at x = 35/2*1.6781= 20.8569(shorter side) \n" ); document.write( "Longer side = [70-(1+pi)*10.4285]/2 = 13.4047 (longer side) \n" ); document.write( "================ \n" ); document.write( "Comment: The method here is correct; the arithmetic may be less \n" ); document.write( "than the accuracy you require. I recommend you check it out. \n" ); document.write( "--------- \n" ); document.write( "Cheers, \n" ); document.write( "Stan H. \n" ); document.write( " \n" ); document.write( " |