I was practising my integration earlier and for one question I got $-\arccos(x - 2)$, while the book has $\arccos(2 - x)$.

The answers seems so close and I was wondering (a) am I right? But more importantly, (b) is there some relationship between $-\arccos(-x)$ and $\arccos x$. More generally, is there a relationship between inverse trig functions and their negatives and what is it?