Approximation of pi Given that $\frac{\pi^2}{6}=\sum_{n=1}^{\infty}\left(\frac{1}{n^2}\right)$, I have to write a program in C that finds an approximation of $\pi$ using the formula $S_n=\sum_{i=1}^{n}\left(\frac{1}{i^2}\right)$.
Then the approximation is: $\sqrt{6\cdot S_n}$
Could you tell me the result for $n=100$ so I can check if my output is right??
Thanks in advance!
Could you tell me why calculating this backwards, it approximates better the sum?

Mathematica is a wonderful tool for these kinds of computations; it is worth learning how to use it, and its baby brother Wolfram Alpha.
Here is what I get: link
