Solution:
SOLUTION
Let $$u=\cfrac{z-1}{{{e}^{\theta i}}}\Rightarrow \cfrac{{{e}^{\theta i}}}{z-1}=\cfrac{1}{u},$$ ,
Now $$\left( u+\cfrac{1}{u} \right)-\left( \bar{u}+\cfrac{1}{{\bar{u}}} \right)=0$$
$$\Rightarrow \left( u-\bar{u} \right)\left( 1-\cfrac{1}{u\bar{u}} \right)=0$$
If u is not purely real, then
$$u\bar{u}=1\Rightarrow \left| \cfrac{z-1}{{{e}^{\theta i}}} \right|=1\Rightarrow \left| z-1 \right|=1$$