fixed ;)
or more simply from = \frac{1+cos\theta-isin\theta}{1+cos\theta}
= \frac{1+cos\theta}{1+cos\theta} - \frac{isin\theta}{1+cos\theta}
= 1 - \frac{isin\theta}{1+cos\theta}
$Let$\,\, t=tan\frac{\theta}{2}, \,\, theta \neq \pi \,\,
$Then$\,\, z = 1 - \frac{i\cdot \frac{2t}{1+t^2}}{1+...