Example 2.10.  Show that the image of the open disk  [Graphics:Images/ComplexFunLinear_gr_282.gif]  under the linear transformation  [Graphics:Images/ComplexFunLinear_gr_283.gif]  is the open disk  [Graphics:Images/ComplexFunLinear_gr_284.gif].  

Explore Solution 2.10.

Enter the function  [Graphics:../Images/ComplexFunLinear_gr_294.gif] .  

[Graphics:../Images/ComplexFunLinear_gr_295.gif]



[Graphics:../Images/ComplexFunLinear_gr_296.gif]

 

 

Solve for the inverse function, i.e. solve for  z  in terms of  w.  Then find [Graphics:../Images/ComplexFunLinear_gr_297.gif].  

[Graphics:../Images/ComplexFunLinear_gr_298.gif]



[Graphics:../Images/ComplexFunLinear_gr_299.gif]

 

 

To solve for [Graphics:../Images/ComplexFunLinear_gr_300.gif],  we use the computations.

[Graphics:../Images/ComplexFunLinear_gr_301.gif]



[Graphics:../Images/ComplexFunLinear_gr_302.gif]

 

 

Which is the disk  [Graphics:../Images/ComplexFunLinear_gr_303.gif]  in the w-plane.  Use Mathematica to graph the transformation.

[Graphics:../Images/ComplexFunLinear_gr_304.gif]



[Graphics:../Images/ComplexFunLinear_gr_305.gif]

[Graphics:../Images/ComplexFunLinear_gr_306.gif]

[Graphics:../Images/ComplexFunLinear_gr_307.gif]

[Graphics:../Images/ComplexFunLinear_gr_308.gif]

We see that the image of the open disk  [Graphics:../Images/ComplexFunLinear_gr_309.gif]  under the transformation  [Graphics:../Images/ComplexFunLinear_gr_310.gif]  is the open disk  [Graphics:../Images/ComplexFunLinear_gr_311.gif].  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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