Solution 3 (e).

See text and/or instructor's solution manual.

Answer.   [Graphics:../Images/SingularityZeroPoleModHome_gr_979.gif]   has removable a singularity at the origin, and a simple pole at  -1.

Solution.   Write   [Graphics:../Images/SingularityZeroPoleModHome_gr_980.gif]

We know that  [Graphics:../Images/SingularityZeroPoleModHome_gr_981.gif]  has a removable singularity at  [Graphics:../Images/SingularityZeroPoleModHome_gr_982.gif],

which implies that  that  [Graphics:../Images/SingularityZeroPoleModHome_gr_983.gif]  has a removable singularity at  [Graphics:../Images/SingularityZeroPoleModHome_gr_984.gif]

Now apply  Corollary 7.5 to conclude that [Graphics:../Images/SingularityZeroPoleModHome_gr_985.gif]  has a simple pole at  -1.

Therefore,  [Graphics:../Images/SingularityZeroPoleModHome_gr_986.gif]  has removable a singularity at the origin, and a simple pole at  -1.  

We are  done.   

Aside.  We can let Mathematica double check our work.

[Graphics:../Images/SingularityZeroPoleModHome_gr_987.gif]

[Graphics:../Images/SingularityZeroPoleModHome_gr_988.gif]


[Graphics:../Images/SingularityZeroPoleModHome_gr_989.gif]

[Graphics:../Images/SingularityZeroPoleModHome_gr_990.gif]

We are really done.   

                    [Graphics:../Images/SingularityZeroPoleModHome_gr_991.gif]

          The removable a singularity at the origin, and a simple pole at  -1.  

                    [Graphics:../Images/SingularityZeroPoleModHome_gr_992.gif]

                              A plot for   [Graphics:../Images/SingularityZeroPoleModHome_gr_993.gif].  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This solution is complements of the authors.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(c) 2008 John H. Mathews, Russell W. Howell