Suppose that $$f(x) = \frac{1}{x} \quad \mathrm{and} \quad g(x) = {3} x^3 - 4 x.$$ For each function $h$ given below, find a formula for $h(x)$ and the domain of $h$.
Note: When entering interval notation in WeBWorK, use I for $\infty$, -I for $-\infty$, and U for the union symbol. If the set is empty, enter "{}" without the quotation marks.
(A)$h(x) = (f \circ g)(x)$.

$h(x)$ =

Domain =
(B) $h(x) = (g \circ f)(x)$.

$h(x)$ =

Domain =
(C) $h(x) = (f \circ f)(x)$.

$h(x)$ =

Domain =
(D) $h(x) = (g \circ g)(x)$.

$h(x)$ =

Domain =