SOLUTION: use S(n)=a1 (1−rn ) / (1−r) to evaluate the series 1/3+1/9+1/27+1/81

Algebra ->  Sequences-and-series -> SOLUTION: use S(n)=a1 (1−rn ) / (1−r) to evaluate the series 1/3+1/9+1/27+1/81      Log On

Hi

r = 1/3

 when |r| < 1, r^n is VERY small