Dave's Math Tables: Geometric Summations
(Math | Calculus | Expansions | Geometric)

SummationExpansionEquivalent ValueComments
  n
sum k x k
k=1
= 1 x1 + 2 x2 + 3 x3 + 4 x4 + ... = x / (x - 1)2  
  inf
sum r k
k=1
= 1 + r + r 2 + r 3 + ... = 1 / (1 - r) Infinite Geometric Series (r not equal to 1)