Exercise 8.  Find the image of the sector  [Graphics:Images/ComplexFunPowerRootModHome_gr_576.gif]  under the following mappings.  

8 (c).  [Graphics:Images/ComplexFunPowerRootModHome_gr_617.gif].  

Solution 8 (c).

See text and/or instructor's solution manual.

Answer.   [Graphics:../Images/ComplexFunPowerRootModHome_gr_618.gif].  

Solution.  Use polar coordinates  [Graphics:../Images/ComplexFunPowerRootModHome_gr_619.gif]  in the z-plane and  [Graphics:../Images/ComplexFunPowerRootModHome_gr_620.gif]  in the  w-plane.  The mapping  [Graphics:../Images/ComplexFunPowerRootModHome_gr_621.gif]  can be written as  

        [Graphics:../Images/ComplexFunPowerRootModHome_gr_622.gif],   

the point  [Graphics:../Images/ComplexFunPowerRootModHome_gr_623.gif]  in the xy-plane is mapped to the point  [Graphics:../Images/ComplexFunPowerRootModHome_gr_624.gif]  in the uv-plane,

and we get the equations  [Graphics:../Images/ComplexFunPowerRootModHome_gr_625.gif]  and  [Graphics:../Images/ComplexFunPowerRootModHome_gr_626.gif].  

Using the equations  [Graphics:../Images/ComplexFunPowerRootModHome_gr_627.gif]  and  [Graphics:../Images/ComplexFunPowerRootModHome_gr_628.gif],  we find that the image of  [Graphics:../Images/ComplexFunPowerRootModHome_gr_629.gif]  is

[Graphics:../Images/ComplexFunPowerRootModHome_gr_630.gif]  which can be written as  [Graphics:../Images/ComplexFunPowerRootModHome_gr_631.gif].  

We are done.   

Aside.  We can let Mathematica double check our work.

                    

                    [Graphics:../Images/ComplexFunPowerRootModHome_gr_632.gif]         [Graphics:../Images/ComplexFunPowerRootModHome_gr_633.gif]

  

                    The image of  [Graphics:../Images/ComplexFunPowerRootModHome_gr_634.gif]  under  [Graphics:../Images/ComplexFunPowerRootModHome_gr_635.gif]  is  [Graphics:../Images/ComplexFunPowerRootModHome_gr_636.gif].  

 

 















 

This solution is complements of the authors.

 

 















 















 

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