Question 628819
"A developer wants to enclose a rectangular grassy lot that borders a city street for parking. If the developer has 300 feet of fencing and does not fence the side along the street, what is the largest area that can be enclosed?"
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Area = L*W
L + 2W = 300 --> L = 300 - 2W
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Area = W*(300 - 2W) = 300W - 2W^2
Area = f(W) = -2W^2 + 300W
That's a parabola whose vertex is the maximum
The axis of symmetry is W = -b/2a = -300/(-4)
W = 75 ft for max area
L = 150 ft
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Area = 75*150 = 11250 sq ft