Module 9 :  Infinite Series, Tests of Convergence,  Absolute and Conditional Convergence, Taylor and Maclaurin Series
Lecture 26 :  Absolute convergence [Section 26.1]
(ii)
Consider the series
 


Apparently, the th term of the series behaves like . Let us consider
and ,
Then
.
Thus

Since the series is also divergent.

(iii)

Consider the series

 

.
The - term of the series will behave like . In fact, if we take
, then

3