SOLUTION: Billy has 52 m of fencing. He wishes to maximize the area of a rectangular garden. What are the dimensions of the rectangle he should use to maximize the area? What is the maximum

Algebra ->  Rectangles -> SOLUTION: Billy has 52 m of fencing. He wishes to maximize the area of a rectangular garden. What are the dimensions of the rectangle he should use to maximize the area? What is the maximum      Log On


   



Question 257085: Billy has 52 m of fencing. He wishes to maximize the area of a rectangular garden. What are the dimensions of the rectangle he should use to maximize the area?
What is the maximum area?
If one side of the rectangular garden is a house and therefore will not require fancing, what dimensions should b used to maximize the area?

Answer by drk(1908) About Me  (Show Source):
You can put this solution on YOUR website!
We have two formulas:
(i) P+=+2L+%2B+2W
(ii) A+=+LW
From the given information, (i) becomes
(iii) 52+=+2L+%2B+2W
or
(iv) 26+=+L+%2B+W
Solving (iv) for L, we get
(v) L+=+26+-+W
substituting (v) into (ii) we get
(vi) A+=+%2826-W%29%28W%29
or
(vii) A+=+-W%5E2+%2B+26W
applying the quadratic, we get
-%28w-13%29%5E2+%2B+13%5E2
so, the dimensions are 13 x 13 and the area is 169 sq. m.
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If one side is a house, then
(i) P+=+L+%2B+2W
(ii) A+=+LW
From the given information, (i) becomes
(iii) 52+=+L+%2B+2W
Solving (iii) for L, we get
(iv) L+=+52+-+2W
substituting (iv) into (ii) we get
(v) A+=+%2852-2W%29%28W%29
or
(vii) A+=+-2W%5E2+%2B+52W
applying the quadratic, we get
-2%28w-13%29%5E2+%2B+52%5E2%2F8
so, the dimensions are 26 x 13 and the area is 338 sq. m.