Exercise 1.  Find  [Graphics:Images/ComplexGeometryContinuedModHome_gr_1.gif]  for the following values of  z.  

1 (e).  [Graphics:Images/ComplexGeometryContinuedModHome_gr_62.gif].  

Solution 1 (e).

See text and/or instructor's solution manual.

One solution is obtained by simplifying the quotient  [Graphics:../Images/ComplexGeometryContinuedModHome_gr_63.gif] as follows:

        [Graphics:../Images/ComplexGeometryContinuedModHome_gr_64.gif]

then

        [Graphics:../Images/ComplexGeometryContinuedModHome_gr_65.gif]  

We are done.   

Another solution is obtained by using the formula  [Graphics:../Images/ComplexGeometryContinuedModHome_gr_66.gif],  where n is an integer.

Since  [Graphics:../Images/ComplexGeometryContinuedModHome_gr_67.gif]  and  [Graphics:../Images/ComplexGeometryContinuedModHome_gr_68.gif] and   [Graphics:../Images/ComplexGeometryContinuedModHome_gr_69.gif]  and  [Graphics:../Images/ComplexGeometryContinuedModHome_gr_70.gif],  an argument of  [Graphics:../Images/ComplexGeometryContinuedModHome_gr_71.gif] is easily found to be

        [Graphics:../Images/ComplexGeometryContinuedModHome_gr_72.gif]

If we choose  [Graphics:../Images/ComplexGeometryContinuedModHome_gr_73.gif],  then  [Graphics:../Images/ComplexGeometryContinuedModHome_gr_74.gif]  lies in the interval[Graphics:../Images/ComplexGeometryContinuedModHome_gr_75.gif],  

so the principal value of the argument is found to be

        [Graphics:../Images/ComplexGeometryContinuedModHome_gr_76.gif]

We are done.   

Aside.  We can let Mathematica double check our work.

        

[Graphics:../Images/ComplexGeometryContinuedModHome_gr_77.gif]

  

[Graphics:../Images/ComplexGeometryContinuedModHome_gr_78.gif]
[Graphics:../Images/ComplexGeometryContinuedModHome_gr_79.gif]
[Graphics:../Images/ComplexGeometryContinuedModHome_gr_80.gif]




















This solution is complements of the authors.



































 

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