• 411 Geometric Series
ᐥThe geometric series ｢a·x˄r Σr=0,∞｣ = a + a·x + a·x² + ... (a≠0) converges if and only if |x|<1. Moreover, its sum is then a/(1−r).ᐥ Partial sum, (1−x)·｢a·x˄r Σr=0,n−1｣ = ｢a·x˄r Σr=0,n−1｣ − ｢a·x˄(r+1) Σr=0,n−1｣ = ｢a·x˄r Σr=0,n−1｣ ┆｢a·x˄(r+1) Σr=0,n−1 ...
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