I am having a little struggle with two questions about deMoivre's theorem and I did not find anything helpful in my books, so I was wondering if anyone here knew it.
First of all I assume that for those particalur questions
are given formulas? (if anyone knows?)
and finally I do not understand how to get from the step where I worked out all z's in my brackets to an answer that makes sense.
Thanks for your time and help