---
tag: KS6D11CVKA
kind: problem
name: Euler's Basel sum
sources:
  - wikipedia: en:20547369@r1336037575
    locator: List of probabilistic proofs of non-probabilistic theorems, section Analysis
    note: adopted
    mention: wikipedia://en/20547369#SW0Y
    sections: [Problem]
inventory: [F60QDK0RNN]
---

## Problem

- [[Euler's Basel sum|0DMY75D6FV]], $\qquad \sum_{n=1}^\infty \frac{1}{n^2} = \frac{\pi^2}{6},$ can be demonstrated by considering the expected exit time of planar Brownian motion from an infinite strip. A number of other less well-known identities can be deduced in a similar manner.