The solution would be like
this for this specific problem:
A = (l + 20) · (w + 10)
The area of the pool is 1800 square feet and can be computed
also like l · w. Then l · w = 1800, and therefore l = 1800 w.
We plug in the values:
A = (1800 / w + 20) · (w + 10) = 1800 + 18000 / w + 20w +
200 = 18000 / w + 20w + 2000
dA /dw = − 18000 / w2 + 20
w = 30
l = 60
Since A = (l + 20) · (w + 10):
A = (60 + 20) · (30+ 10)
A = 3,200
A(x) = 1800 + 2*10(x+10)+ 2*5(1800/x)
= 1800 + 20x + 200 + 18000/x
= 2000 + 20 x + 18000/x
20 - 18000/x^2 = 0
x = sqrt (900) = 30
Pool length dimension = 1800/x = 60
Lot dimensions: 80 x 40
I am hoping that these answers
have satisfied your queries and it will be able to help you in your endeavors, and
if you would like, feel free to ask another question.
