The 5 values of $(1+\mathrm{i})^{3 / 5}$ are given by $2^{3 / 10}\left[\cos \left(\frac{3 \pi}{20}+\frac{6 \mathrm{k} \pi}{5}\right)+\mathrm{i} \sin \left(\frac{3 \pi}{20}+\frac{6 \mathrm{k} \pi}{5}\right)\right]$, where $\mathrm{k}=0,1,2,3,4$
and
Statement 2 If $z=r(\cos \alpha+i \sin \alpha)$ and $n$ is a positive integer, the $n$ values of $z^{1 / n}$ are given by $r^{1 / n}\left(\cos \left(\frac{\alpha}{n}+\frac{2 k \pi}{n}\right)+i \sin \left(\frac{\alpha}{n}+\frac{2 k \pi}{n}\right)\right.$
$\mathrm{k}=0,1,2, \ldots \ldots, \mathrm{n}-1$