I am looking for a more accurate rewritten formula (than below) for computing the sides of polygon with 3*2^n sides (approximating a circle). Any tip where to focus, what kind of computations I need to do? I would be thankful for any suggestion.

x_{n}=sqrt{2-2 sqrt{1-( x_{n-1}/2)²}}

Question

I am looking for a more accurate rewritten formula (than below) for computing the sides of polygon with 3*2^n sides (approximating a circle). Any tip where to focus, what kind of computations I need to do? I would be thankful for any suggestion.

x_{n}=sqrt{2-2 sqrt{1-( x_{n-1}/2)²}}

anonymous · Answer

$$x_{n}=\sqrt{2-2 \sqrt{1-( x_{n-1}/2)²}}$$