Example 2.19. Show
that
.
Solution. Here P and
Q can be factored in the
form
![[Graphics:Images/ComplexFunLimitMod_gr_271.gif]](../Images/ComplexFunLimitMod_gr_271.gif)
so that the limit is obtained by the calculation
Explore Solution 2.19.
Enter the function f[z] and find the limit.
Try to evaluate f[1+i].
![[Graphics:../Images/ComplexFunLimitMod_gr_276.gif]](../Images/ComplexFunLimitMod_gr_276.gif)
Let Mathematica take the limit.
Check out the details.
Factor the numerator and denominator of f[z].
![[Graphics:../Images/ComplexFunLimitMod_gr_280.gif]](../Images/ComplexFunLimitMod_gr_280.gif)
Find the limit of f[z] as z approaches 1 + i.
![[Graphics:../Images/ComplexFunLimitMod_gr_282.gif]](../Images/ComplexFunLimitMod_gr_282.gif)
We can use Mathematica to make a mapping of a neighborhood
of
in
the z-plane and its image in the w-plane.
![[Graphics:../Images/ComplexFunLimitMod_gr_285.gif]](../Images/ComplexFunLimitMod_gr_285.gif)
![[Graphics:../Images/ComplexFunLimitMod_gr_287.gif]](../Images/ComplexFunLimitMod_gr_287.gif)
![[Graphics:../Images/ComplexFunLimitMod_gr_288.gif]](../Images/ComplexFunLimitMod_gr_288.gif)
We see that
.
(c) 2006 John H. Mathews, Russell W. Howell