A Proof of Ramanujan's Classic $\ddot{I}€$ Formula

Thang Pang Ern, Devandhira Wijaya Wangsa

In 1914, Ramanujan presented a collection of 17 elegant and rapidly converging formulae for $\ddot{I}€$. Among these, one of the most celebrated is the following series: \[\frac{1}π=\fra…