Optimization - area of rectangle

look416 · Jan 11, 2010

Homework Statement

If the perimeter of a rectangle is fixed in length, show that the area of the rectangle is greatest when it is square

if the perimeter is fixed in length, then 2x + 2y = c
then no idea to continue from there

Dick · Jan 11, 2010

Ok so far. Now you want to maximize x*y, right? Eliminate one of the variables using the perimeter condition and differentiate, etc.

rock.freak667 · Jan 11, 2010

look416 said:

The Attempt at a Solution

if the perimeter is fixed in length, then 2x + 2y = c
then no idea to continue from there

So what is the area A in terms of x and c?