Example 4.6. Show
that the series
is
convergent.
Solution. We calculate
. Using
the comparison test and the fact that
converges,
we determine that
converges
and hence, by Corollary 4.1, so does
.
Explore Solution 4.6.
Enter the formula for the series, and determine if the series converges or diverges.
![[Graphics:../Images/ComplexSequenceSeriesMod_gr_275.gif]](../Images/ComplexSequenceSeriesMod_gr_275.gif)
![[Graphics:../Images/ComplexSequenceSeriesMod_gr_276.gif]](../Images/ComplexSequenceSeriesMod_gr_276.gif)
Hence we see that the series converges and
that
.
Or we could use Corollary 4.1 and show that the series converges
absolutely.
![[Graphics:../Images/ComplexSequenceSeriesMod_gr_279.gif]](../Images/ComplexSequenceSeriesMod_gr_279.gif)
The series of absolute values converges, therefore the series
converges.
Use Mathematica to construct some of the partial sums of the
infinite series.
![[Graphics:../Images/ComplexSequenceSeriesMod_gr_281.gif]](../Images/ComplexSequenceSeriesMod_gr_281.gif)
Use Mathematica to construct some of the partial sums of the infinite series.
![]()
![[Graphics:../Images/ComplexSequenceSeriesMod_gr_284.gif]](../Images/ComplexSequenceSeriesMod_gr_284.gif)
Use Mathematica to compute more of the partial sums of the infinite series.
![[Graphics:../Images/ComplexSequenceSeriesMod_gr_286.gif]](../Images/ComplexSequenceSeriesMod_gr_286.gif)
Use Mathematica to plot some of the partial sums of the infinite series.
![[Graphics:../Images/ComplexSequenceSeriesMod_gr_288.gif]](../Images/ComplexSequenceSeriesMod_gr_288.gif)
![[Graphics:../Images/ComplexSequenceSeriesMod_gr_289.gif]](../Images/ComplexSequenceSeriesMod_gr_289.gif)
Therefore, we see that the series converges, and we
have
.