Consider the function $f(z) = \sqrt{z^2 +1}$, that is, the principal value of the function $(z^2 +1)^{1/2}$. Determine the branch cuts of $f(z)$; check the discontinuity of the branch along the branch cuts.
This is the problem i was given. My problem is that i have no idea what branch cuts are. This year the course got a new professor who just copied a lot of stuff from the last but his lectures are very behind so he hasn't explained what those are and i cant find it in the book.
(and i am an astronomy student following an mandatory math course(complex analysis) so it might have been explained in earlier courses for math students i dont know).
Can someone please explain what i have to do with the branches?
