## tejasree 2 years ago A farmer has 336 ft of fencing and wants to build two identical pens for his prize-winning pigs. The pens will be arranged as shown. Determine the dimensions of a pen that will maximize its area.

1. tejasree

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2. petewe

Fencing = 3x + 4y 336 = 3x + 4y Area = 2xy A = 2xy x = (336-4y) / 3 A = 2[(336-4y)/3] y Find dA/dy and equate to 0. solve for y.

3. tejasree

I dont understand this part: x = (336-4y) / 3 A = 2[(336-4y)/3] y Find dA/dy and equate to 0. solve for y.

4. petewe

i rearranged the fencing equation in terms of x and subbed it into the area equation. find the derivative of A with respect to y. make it equal 0. solve for y. sub y into original equation and solve for x.

5. tejasree

I dont know deriatives yet!

6. tejasree

pls help me! I have to study for my final exam!!!

7. petewe

instead of taking the derivative, find the vertex of the quadratic equation.

8. tejasree

ok! I will try and call for you when I dont get it!

9. petewe

the x value of your vertex will be y