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Farmer Ed has 450 meters of fencing, and wants to enclose a rectangular plot tha

ID: 3115851 • Letter: F

Question

Farmer Ed has 450 meters of fencing, and wants to enclose a rectangular plot that borders on a river. If Farmer Ed does not fence the side along the river, find the length and width of the plot that will maximize the area. What is the largest area that can be enclosed? 450 -2x The width, labeled x in the figure, is meters. (Type an integer or decimal.) The length, labeled 450-2x in the figure, is meters. Type an integer or decimal.) The largest area that can be enclosed is square meters. Type an integer or decimal.)

Explanation / Answer

length = 450 - 2x

width = x

area = length * width

A(x) = x ( 450 - 2x )

= -2x^2 + 450x

maximum area occurs at x = -b / 2a = -450 / 2(-2)

width x = 112.5 metres

length = 450 - 2 ( 112.5)

length = 225 metres

largest area = -2(112.5)^2 + 450(112.5)

largest area = 25312.5 square metres