Let $\displaystyle z = \frac{128}{\sqrt2}(1 + i)$. What are all possible solutions of:

$\displaystyle w = z^{1/7}$

So, after converting to polar form I have:

$\displaystyle z^{1/7} = 2(cos\left(\frac{\pi}{28}\right)+i~sin\left(\frac{ \pi}{28}\right))$

I have the answer which includes 7 solutions and I'm a little confused on how to get to them. I guess this is more a trig question?