Module 9 :  Infinite Series, Tests of Convergence,  Absolute and Conditional Convergence, Taylor and Maclaurin Series
Lecture 26 :  Absolute convergence [Section 26.1]
26.1.8

Note (Basic strategy for testing convergence):

(i)

As a general rule, check . If

 

, the series is divergent.
If try convergent tests as suggested next.

(ii)
If is a decreasing sequence of positive terms, such that for some function

try Integral test.

(iii)
If is a rational function, or is some root of , try limit comparison test.
(iv)
Some of the standard series for comparison test are: Geometric series, p-series.
(v)
Ratio test is useful if has factorial/ powers of
(vi)

Root test is useful, if it is series to find root of

   
  Practice Exercises
1.

Using limit comparison test, determine the convergence/ divergence of the following series:

(i)
.
(ii)
.
(iii)
(Hint glows more slowly than for every )
  Answers
9