The volume of a rectangular prism with a square base is fixed at cubic feet.

Volume of a rectangular prism is :  .

The width of a rectangular prism is .

Since it is a rectangular prism length and width are equal.

Substitute , and in .

.

(a)

Find surface area of prism.

Surface area of prism .

Substitute , and in .

Surface area of prism .

(b)

Graph :

Graph the surface area of the function .

(c)

Surface area of prism .

As the length of the side approaches to , surface area of the prism approaches to infinity.

(a)

Surface area of prism .

(b)

Graph :

Graph the surface area of the function .

(c)

The length of the side approaches to , surface area of the prism approaches to infinity.