# partial sums of sequences

• March 2nd 2010, 06:31 AM
confusedgirl
partial sums of sequences
find the Sn of An = 1/2^n
• March 2nd 2010, 06:49 AM
Krizalid
geometric sum for $a=\frac12$ where $\sum_{j=0}^na^j=\frac{a^{n+1}-1}{a-1}.$