Exercise 1.  Find the following limits.  

1 (c).  [Graphics:Images/ComplexFunLimitModHome_gr_27.gif].  

Solution 1 (c).

See text and/or instructor's solution manual.

Answer.  [Graphics:../Images/ComplexFunLimitModHome_gr_28.gif].

Solution.  Substituting  [Graphics:../Images/ComplexFunLimitModHome_gr_29.gif]  will result in the "[Graphics:../Images/ComplexFunLimitModHome_gr_30.gif]" situation.  

        [Graphics:../Images/ComplexFunLimitModHome_gr_31.gif]

        Indeterminate

We can factor the numerator and denominator and get:  

        [Graphics:../Images/ComplexFunLimitModHome_gr_32.gif]

We are done.   

Aside.  We can let Mathematica double check our work.

[Graphics:../Images/ComplexFunLimitModHome_gr_33.gif]
[Graphics:../Images/ComplexFunLimitModHome_gr_34.gif]



                    [Graphics:../Images/ComplexFunLimitModHome_gr_35.gif]          [Graphics:../Images/ComplexFunLimitModHome_gr_36.gif]

  

                    The mapping  [Graphics:../Images/ComplexFunLimitModHome_gr_37.gif],  as  [Graphics:../Images/ComplexFunLimitModHome_gr_38.gif],  the image point  [Graphics:../Images/ComplexFunLimitModHome_gr_39.gif],

                    and we see that   limit   [Graphics:../Images/ComplexFunLimitModHome_gr_40.gif].  

Alternate Solution.  In Section 7.5 we will present the conditions under which L'Hôpital's rule is valid.  For most practical purposes it will appear similar to the rule learned in calculus.

        [Graphics:../Images/ComplexFunLimitModHome_gr_41.gif]   

Remark.  For this type of problem L'Hôpital's rule is faster.

[Graphics:../Images/ComplexFunLimitModHome_gr_42.gif]

[Graphics:../Images/ComplexFunLimitModHome_gr_43.gif]


[Graphics:../Images/ComplexFunLimitModHome_gr_44.gif]

[Graphics:../Images/ComplexFunLimitModHome_gr_45.gif]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 



This solution is complements of the authors.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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