Why is pi here? And why is it squared? A geometric answer to the Basel problem - YouTube
sequences and series - Why does the sum of inverse squares equal $\pi^2/6$? - Mathematics Stack Exchange
Basel problem - Wikipedia
Given that sum(n=1)^oo 1/n^2=pi^2/6 and sum(n=1)^oo 1/(n^2+8n+16)=pi^2/a-b where a in N and b in Q , then a is equal to
Basel problem - Wikipedia
Wallis product - Wikipedia
Solved In one of the following problems, you will need to | Chegg.com
Proof by intuition done by Leonhard Euler, sum of 1/n^2, (feat. Max) - YouTube
What's an intuitive explanation of the following mathematical fact: [math]\displaystyle \sum_{n=1}^{\infty}{\frac{1}{n^2}} = \frac{\pi^2}{6}[/math]? - Quora
Basel problem - Wikipedia
Prove some formulas for given infinite sums - Stumbling Robot
prove the following identity of Euler: sigma_n - | Chegg.com