I've got this integral on top and I have to find it using the cauchy's integral formula and I tried this approach to solve it.
I know how to apply the formula but I just need help solving this part because it's been a long time since I last used the partial fractions method.
Regarding the |z|= 4, just forget it, I am going to use it somewhere else.
I think I am doing something wrong and I know that I shouldn't stop here, but I want to make sure that what I'm doing is correct.
This is the final answer that I found.