When performing a RootOf command on a polynomial how would you then extract the polynomial itself from the result?

I.e. If i were to set A:= RootOf(x^2-1) Maple would then return A = RootOf(_Z^2-1), so what command performed on A is needed to give me just _Z^2-1 (or even better x^2-1)?

Sorry if this is horribly worded  :(