Corollary 6.1.  Let    denote a fixed complex value.  If C is a simple closed contour with positive orientation such that    lies interior to C, then

(i)                  ,   and  

Demonstration for (i).

(a)   Show that .  
For illustration.  We use a circle of radius 1 centered at  .  

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