Example 1.10.  If  ,  then  

               and  

            .  

It would be a mistake to use as an acceptable value for , as the point z associated with and is in the first quadrant, whereas is in the third quadrant.  A correct choice for is .  Thus

            ,  and

            ,
            
where n is any integer.  In this case,

            ,  and

            .

Explore Solution 1.10.

Here is another way to look at it.

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