25.4k views
5 votes
you wish to make a rectangular pen in your backyard for a garden. you have 25 feet of fencing. what is the maximum area of the garden?

User Dan Taylor
by
8.3k points

1 Answer

2 votes

The maximum area of the rectangular garden, obtained by solving the optimization problem, is 625/16 square feet.

Certainly! Let's solve the optimization problem step by step:

Given:

2l + 2w = 25

We can solve for l in terms of w:

l + w = 25/2

l = 25/2 - w

Now, express the area A in terms of w:

A = lw

A = (25w/2 - w^2)

Expand and simplify the equation:

A = 25w/2 - w^2

To find the critical points, take the derivative of A with respect to w and set it equal to zero:

dA/dw = 25/2 - 2w

Setting dA/dw = 0:

25/2 - 2w = 0

-2w = -25/2

w = 25/4

Now, substitute w = 25/4 back into the equation for l:

l = 25/2 - 25/4

l = 25/4

So, the dimensions that maximize the area are l = 25/4 and w = 25/4.

Finally, calculate the maximum area:

A_max = (25/4) * (25/4)

A_max = 625/16

Therefore, the maximum area of the rectangular garden is 625/16 square feet.

User Dan Bolser
by
8.3k points