Example 2.24.  Consider the mapping  [Graphics:Images/ComplexFunReciprocalMod_gr_154.gif].   
(a)  Find the images of the vertical lines  x = a.   (b)  Find the images the horizontal lines  y = b.  

Explore Solution 2.24.

(a)  First, find the images of the vertical lines  x = a.

[Graphics:../Images/ComplexFunReciprocalMod_gr_167.gif]



[Graphics:../Images/ComplexFunReciprocalMod_gr_168.gif]

 

 

The image of the vertical lines  x = a  is the circle[Graphics:../Images/ComplexFunReciprocalMod_gr_169.gif],  with center  [Graphics:../Images/ComplexFunReciprocalMod_gr_170.gif]  and radius  [Graphics:../Images/ComplexFunReciprocalMod_gr_171.gif].  

(b)  Second, find the images the horizontal lines  y = b.

[Graphics:../Images/ComplexFunReciprocalMod_gr_172.gif]



[Graphics:../Images/ComplexFunReciprocalMod_gr_173.gif]

 

 


The image is the circle[Graphics:../Images/ComplexFunReciprocalMod_gr_174.gif],  with center  [Graphics:../Images/ComplexFunReciprocalMod_gr_175.gif]  and radius  [Graphics:../Images/ComplexFunReciprocalMod_gr_176.gif].  

Now prepare some horizontal and vertical lines in Mathematica for graphing.

[Graphics:../Images/ComplexFunReciprocalMod_gr_177.gif]


Now prepare the image circles in Mathematica for graphing.

[Graphics:../Images/ComplexFunReciprocalMod_gr_178.gif]

Graph the horizontal and vertical lines and their images.

[Graphics:../Images/ComplexFunReciprocalMod_gr_179.gif]



[Graphics:../Images/ComplexFunReciprocalMod_gr_180.gif]

[Graphics:../Images/ComplexFunReciprocalMod_gr_181.gif]

[Graphics:../Images/ComplexFunReciprocalMod_gr_182.gif]

[Graphics:../Images/ComplexFunReciprocalMod_gr_183.gif]


We see that the images of the vertical lines  x = a  and  horizontal lines  y = b  under the mapping  [Graphics:../Images/ComplexFunReciprocalMod_gr_184.gif] are circles.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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