2011/10/09

[48] Geometric series/等比数列の和 Σa_k = a(1-r^n) / 1-r (when r≠1)

https://www.evernote.com/shard/s29/sh/f2c30088-c485-424e-8502-fdb56c95c1cf/4d51d96ffbca186c2401ea9966d4b1bf