Exercise 1.  Let  [Graphics:Images/ComplexFunBranchModHome_gr_1.gif]  and  [Graphics:Images/ComplexFunBranchModHome_gr_2.gif]  be the two branches of the square root function given by Equations (2-28) and (2-29), respectively.  

(2-28)            [Graphics:Images/ComplexFunBranchModHome_gr_3.gif][Graphics:Images/ComplexFunBranchModHome_gr_4.gif][Graphics:Images/ComplexFunBranchModHome_gr_5.gif],  

(2-29)            [Graphics:Images/ComplexFunBranchModHome_gr_6.gif][Graphics:Images/ComplexFunBranchModHome_gr_7.gif][Graphics:Images/ComplexFunBranchModHome_gr_8.gif],    

            where  [Graphics:Images/ComplexFunBranchModHome_gr_9.gif]  and  [Graphics:Images/ComplexFunBranchModHome_gr_10.gif] so that  [Graphics:Images/ComplexFunBranchModHome_gr_11.gif].  

Use the polar coordinate formulas in Section 2.2 to find the image of

1 (a).  Quadrant II,  [Graphics:Images/ComplexFunBranchModHome_gr_12.gif],  under the mapping  [Graphics:Images/ComplexFunBranchModHome_gr_13.gif].  

Solution 1 (a).

See text and/or instructor's solution manual.

Answer.  The sector [Graphics:../Images/ComplexFunBranchModHome_gr_14.gif].

Solution.  Use polar coordinates  [Graphics:../Images/ComplexFunBranchModHome_gr_15.gif]  in the z-plane and  [Graphics:../Images/ComplexFunBranchModHome_gr_16.gif]  in the  w-plane.  

Then  [Graphics:../Images/ComplexFunBranchModHome_gr_17.gif]  

maps the point  [Graphics:../Images/ComplexFunBranchModHome_gr_18.gif]  in the xy-plane onto the point  [Graphics:../Images/ComplexFunBranchModHome_gr_19.gif]  in the uv-plane,

and we get the equations  [Graphics:../Images/ComplexFunBranchModHome_gr_20.gif]  and  [Graphics:../Images/ComplexFunBranchModHome_gr_21.gif].  

Using the equations  [Graphics:../Images/ComplexFunBranchModHome_gr_22.gif]  and  [Graphics:../Images/ComplexFunBranchModHome_gr_23.gif],  we find that the image of Quadrant II ;  [Graphics:../Images/ComplexFunBranchModHome_gr_24.gif]  is  

[Graphics:../Images/ComplexFunBranchModHome_gr_25.gif]  which can be written as  [Graphics:../Images/ComplexFunBranchModHome_gr_26.gif].  

We are done.   

Aside.  We can let Mathematica double check our work.

          

                     [Graphics:../Images/ComplexFunBranchModHome_gr_27.gif]          [Graphics:../Images/ComplexFunBranchModHome_gr_28.gif]

  

                    The mapping  [Graphics:../Images/ComplexFunBranchModHome_gr_29.gif].

                    The domain set  [Graphics:../Images/ComplexFunBranchModHome_gr_30.gif]  and range set  [Graphics:../Images/ComplexFunBranchModHome_gr_31.gif].

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This solution is complements of the authors.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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