Example 10.10.  Show that the transformation  [Graphics:Images/MapElementaryFunMod_gr_77.gif]  is a one-to-one conformal mapping of the portion of the unit disk  [Graphics:Images/MapElementaryFunMod_gr_78.gif]  that lies in the upper half-plane  [Graphics:Images/MapElementaryFunMod_gr_79.gif]  onto the upper half-plane  [Graphics:Images/MapElementaryFunMod_gr_80.gif].  Furthermore, the upper semicircular portion of the boundary is mapped onto the line negative u-axis, and the segment  [Graphics:Images/MapElementaryFunMod_gr_81.gif]  is mapped onto the positive u-axis.

Figure 10.12  The composite transformation  [Graphics:Images/MapElementaryFunMod_gr_91.gif].

Explore Solution 10.10.

Enter the function  [Graphics:../Images/MapElementaryFunMod_gr_92.gif].  

[Graphics:../Images/MapElementaryFunMod_gr_93.gif]


[Graphics:../Images/MapElementaryFunMod_gr_94.gif]

 

 

To show  [Graphics:../Images/MapElementaryFunMod_gr_95.gif]  is one-to-one conformal we need to find the inverse function.  Since there is two branches, one of them is appropriate for this problem.

[Graphics:../Images/MapElementaryFunMod_gr_96.gif]



[Graphics:../Images/MapElementaryFunMod_gr_97.gif]

 

 

 

The image is traced using a graph.

[Graphics:../Images/MapElementaryFunMod_gr_98.gif]





[Graphics:../Images/MapElementaryFunMod_gr_99.gif]

[Graphics:../Images/MapElementaryFunMod_gr_100.gif]

[Graphics:../Images/MapElementaryFunMod_gr_101.gif]

[Graphics:../Images/MapElementaryFunMod_gr_102.gif]


We see that the transformation  [Graphics:../Images/MapElementaryFunMod_gr_103.gif]  maps the portion of the unit disk  [Graphics:../Images/MapElementaryFunMod_gr_104.gif]  that lies in the upper half-plane  [Graphics:../Images/MapElementaryFunMod_gr_105.gif]  onto the upper half-plane  [Graphics:../Images/MapElementaryFunMod_gr_106.gif].

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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