Given that \( f(x)=1-x^{2} \) and \( g(x)=\sqrt{x^{2}-1} \), determine the following;
(a) The domain and range of \( f(x) \) and \( g(x) \)
(b) \( (f \circ g)(x) \) and \( (g \circ f)(x) \)
(c) \( f^{-1}(x) \) and \( g^{-1}(x) \) determine;
(a) The values of \( a, b \), and \( p \)
(b) The roots of \( f(x) \)