The problem of determining the value of $\zeta (2)$ also known as t...
Tom Mike Apostol was an American analytic number theorist and profe...
If you want to learn more about Apéry's proof click [here](https://...
Here the author uses the formula for the sum of a geometric series ...
Note that $\int_{0}^{1} x^n dx= \left[ \frac{x^{n+1}}{n+1}\right]_{...
With this change of variables we change the region and limits of in...
Alternatively we could note that $$ \frac{d}{du} \arctan \frac{...