Example 4.6.  Show that the series  [Graphics:Images/ComplexSequenceSeriesMod_gr_269.gif]  is convergent.

Solution.  We calculate  [Graphics:Images/ComplexSequenceSeriesMod_gr_270.gif].    Using the comparison test and the fact that  [Graphics:Images/ComplexSequenceSeriesMod_gr_271.gif]  converges, we determine that  [Graphics:Images/ComplexSequenceSeriesMod_gr_272.gif]  converges and hence, by Corollary 4.1, so does [Graphics:Images/ComplexSequenceSeriesMod_gr_273.gif].

Explore Solution 4.6.

Enter the formula for the series, and determine if the series converges or diverges.

[Graphics:../Images/ComplexSequenceSeriesMod_gr_274.gif]




[Graphics:../Images/ComplexSequenceSeriesMod_gr_275.gif]

[Graphics:../Images/ComplexSequenceSeriesMod_gr_276.gif]

 

 

Hence we see that the series converges and that  [Graphics:../Images/ComplexSequenceSeriesMod_gr_277.gif].  
Or we could use Corollary 4.1 and show that the series converges absolutely.  

[Graphics:../Images/ComplexSequenceSeriesMod_gr_278.gif]




[Graphics:../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_280.gif]




[Graphics:../Images/ComplexSequenceSeriesMod_gr_281.gif]

 

 

Use Mathematica to construct some of the partial sums of the infinite series.

[Graphics:../Images/ComplexSequenceSeriesMod_gr_282.gif]




[Graphics:../Images/ComplexSequenceSeriesMod_gr_283.gif]

[Graphics:../Images/ComplexSequenceSeriesMod_gr_284.gif]

 

 

Use Mathematica to compute more of the partial sums of the infinite series.

[Graphics:../Images/ComplexSequenceSeriesMod_gr_285.gif]




[Graphics:../Images/ComplexSequenceSeriesMod_gr_286.gif]

 

 

Use Mathematica to plot some of the partial sums of the infinite series.

[Graphics:../Images/ComplexSequenceSeriesMod_gr_287.gif]





[Graphics:../Images/ComplexSequenceSeriesMod_gr_288.gif]

[Graphics:../Images/ComplexSequenceSeriesMod_gr_289.gif]

Therefore, we see that the series converges, and we have  [Graphics:../Images/ComplexSequenceSeriesMod_gr_290.gif].  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(c) 2006 John H. Mathews, Russell W. Howell