6. Consider the functions \( f(x)=3 x-1 \) and \( g(x)=x^{2}-4 \). Find the functions \[ (f+g)(x),(f-g)(x),(f g)(x),(f / g)(x),(f \circ g)(x),(g \circ f)(x), f^{-1}(x) \] Then evaluate each at \( x=-1