For n > 1, I have designated the value of log_n(pi+1/log_n(pi+1/log_n(pi+...))) as the function pin(n). Inversely, given pin (8)=0.72544666, how do you approximate pi?

1 Answer
Aug 3, 2016

pi = 8^(0.72544666)-1/(0.72544666) ~~ 3.1415928

Explanation:

Suppose:

t = log_n(pi+1/(log_n(pi+1/(log_n(pi+...)))))=log_n(pi+1/t)

Then:

n^t = pi+1/t

So:

pi = n^t-1/t

In our example, we are told that n = 8 and t = 0.72544666

So:

pi = 8^(0.72544666)-1/(0.72544666)

~~ 4.5200539-1.3784611 = 3.1415928