SOLUTION: Determine if the following series are convergent of divergent. If the series is geometric find the sum as well: [cos(n*pi/3)] / n factorial at n =1 to infinity Thank you s

Algebra ->  Sequences-and-series -> SOLUTION: Determine if the following series are convergent of divergent. If the series is geometric find the sum as well: [cos(n*pi/3)] / n factorial at n =1 to infinity Thank you s      Log On


   

Question 579910: Determine if the following series are convergent of divergent. If the series is geometric find the sum as well:
[cos(n*pi/3)] / n factorial
at n =1 to infinity

Thank you so much!
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
It is not a geometric series.
-1%3C=cos%28n%2Api%2F3%29+%3C=1, and n%21 (n factorial) grows without bounds , so a%5Bn%5D=cos%28n%2Api%2F3%29%2Fn%21 converges to zero