Damon help again :) (last one I promise)

why is X along the road sqrt2/2?

] A rancher plans to set aside a rectangular region of one square kilometer for cattle and wishes to build a wooden fence to enclose the region. Since one side of the region will run along the road, the rancher decides to use a better quality wood for that side which costs three times as much as the wood for the other sides. What dimensions will minimize the cost of the fence?

x y = 1

c = 3 x + x + 2 y = 4 x + 2 y

c = 4 x + 2/x

dc/dx = 4 - 2/x^2
= 0 for minimum

4 = 2/x^2
x^2 = 1/2
x = 1/sqrt 2 = sqrt 2/2 along road
y = sqrt 2

3 answers

This question has already been answered by Damon
Yes, I know, but I i had question about the answer... I'm math stupid :)
The smaller of x or y will be the expensive fence along the road.
Similar Questions
  1. Assume that no denominator equals 0.sqrt12 - sqrt18 + 3sqrt50 + sqrt75 = (sqrt2^2*3) - (sqrt2*3^2) + (3sqrt2*5^2) + (sqrt3*5^2)
    1. answers icon 1 answer
  2. Given: f(x) = X^2-xevaluate: f(sqrt2 + 3) I have worked out this and am stuck: (sqrt2+3)^2 - (sqrt2+3) (sqrt2+3)*(sqrt2+3)-
    1. answers icon 2 answers
  3. Hi--can anybody show me how to do this?Find the length of the curve r(t)= (sqrt2)i + (sqrt2)j + (1-t^2)k from (0,0,1) to (sqrt2,
    1. answers icon 1 answer
    1. answers icon 1 answer
more similar questions