Question 569291
You have a rectangle with 78 square centimeters.What are the dimensions of the rectangle with the largest perimeter? 
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Equation:
LW = 78 sq. cm
Perimeter = 2(L + W)
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P = 2(L + (78/L))
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P = 2(L^2+78)/L
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P = (2L^2+156)/L
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Take the derivative:
P' = [L(4L)-(2L^2+156)]/L^2
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P' = [2L^2-156]/L^2
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Solve: P' = 0
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2L^2-156 = 0
L^2 = 78
Length = sqrt(78)
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Width = sqrt(78)
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Cheers,
Stan H.
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