1. ## express area

I know the answers but I would like to know the solutions too...

1. Express the perimeter of a square as a function of its area A

2. Express the area of a circle as a function of its diamter d

3. Express the diameter of a circle as a function of its circumference C

4. Express the volume of a cube as the function of the area A of its base.

thanks!!

2. Originally Posted by skabani
1. Express the perimeter of a square as a function of its area A
I'll do the first, the rest are similar.

A square has 4 sides of the same length, call it s.

So the perimeter is
$P = 4s$

The area of the square is
$A = s^2$

So
$s = \sqrt{A}$

Thus the perimeter is
$P = 4s = 4(\sqrt{A}) = 4 \sqrt{A}$

-Dan