# expansio

1. ### Laurentz expansio

Hey all, how can I expand (z^2)/(Z^2)-1 around 0 and valid for z<1 This was in previous exam, lecturer wasn't very helpful..
2. ### representation of a arccos as taylor expansio

I'm having trouble expressing arccos(x) as a Maclaurin series. I realized that once you differentiate it, the function will just expand rapidly, so is there a easy way approaching this problem.