This is LaTeX code:

[latex]
\frac{1}{(z+1)}=\frac{1}{(z-i)+1+i}=\frac{1}{1+i}\frac{1}{\frac{z-i}{1+i}+1}=\sum_{n=0}^{\infty}\frac{(z-i)^n}{(1+i)^{n+1}}}
[/latex]