Chapter 8.5, Problem 59PS

(a)

To determine

To show: ${\displaystyle \sum a_n}$ converges or not.

(b)

To determine

To find: ${\displaystyle \sum a_n}$ diverges or not and explain the reason why $a_n>1$

(c)

To determine

To find: two series ${\displaystyle \sum a_n}$ and ${\displaystyle \sum b_n}$