Example 2.17.  Show that  [Graphics:Images/ComplexFunLimitMod_gr_158.gif].   

Solution.  We have  

            [Graphics:Images/ComplexFunLimitMod_gr_159.gif]  

Computing the limits for u and v, we obtain  

            [Graphics:Images/ComplexFunLimitMod_gr_160.gif],  and
            
            [Graphics:Images/ComplexFunLimitMod_gr_161.gif],  

so our previous theorem implies that [Graphics:Images/ComplexFunLimitMod_gr_162.gif].  

Explore Solution 2.17.

Enter the function f[z] and find the limit.

[Graphics:../Images/ComplexFunLimitMod_gr_163.gif]




[Graphics:../Images/ComplexFunLimitMod_gr_164.gif]

 

 

 

We can use Mathematica to make a mapping of a neighborhood of  [Graphics:../Images/ComplexFunLimitMod_gr_165.gif]  in the z-plane and its image in the w-plane.

[Graphics:../Images/ComplexFunLimitMod_gr_166.gif]




[Graphics:../Images/ComplexFunLimitMod_gr_167.gif]

[Graphics:../Images/ComplexFunLimitMod_gr_168.gif]

[Graphics:../Images/ComplexFunLimitMod_gr_169.gif]

[Graphics:../Images/ComplexFunLimitMod_gr_170.gif]

We see that  [Graphics:../Images/ComplexFunLimitMod_gr_171.gif].  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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