# Math Help - Express as a Function.

1. ## Express as a Function.

A rectangle has area 64 m2.

(a) Express the perimeter of the rectangle as a function of the length (L) of one of its sides.

I came up with A(L) = 2x + (128/x) or 2L + (128/L)

(b) State its domain.

How do I state its domain?

Is it [0, INFINITY) ?

2. ## Re: Express as a Function.

Originally Posted by NeoSonata
or 2L + (128/L)

Yep!

Originally Posted by NeoSonata

Is it [0, INFINITY) ?
You're on the right track here, it can't be zero or we wouldn't have a rectangle.