The series is
.
Here
.
Check whether the function is decreasing or not.
\
Differentiate on each side.
\

Test the function for
.


As
the function is decreasing.
Thus, the function is continuous and decreasing.
\Perform integral test.
\Integral test:
\If
is convergent then
is convergent.
Here
.
Find
.

.
Formula for integration by parts :
.
Let
and 
.
Apply integral on each side.
\
Substitute corresponding values in the integration by parts formula.
\
Consider
.
.
Again apply integration by parts.
\Let
and
.
.

Substitute corresponding values in the integration formula.
\
Substitute above result in (1).
\

Apply L hospital rule for
.


= a finite number.
\ Therefore,
is convergent.
Thus by the integral test series
is also convergent.
Series is convergent.