If z=1+itan(α)1−itan(α)z = \frac{1+i\tan(\alpha)}{1-i\tan(\alpha)}z=1−itan(α)1+itan(α), which of the following is equivalent to zzz?
cos(2α)+isin(2α)\cos(2\alpha) + i\sin(2\alpha)cos(2α)+isin(2α)
eiαe^{i\alpha}eiα
tan(2α)\tan(2\alpha)tan(2α)
1+itan(2α)1 + i\tan(2\alpha)1+itan(2α)