Plot a Function over Its Domain
Symbolically determine the domain for a function and plot over it.
In[1]:=

f = Sqrt[x^3 - x]/(x^2 + 1)
Out[1]=

In[2]:=

domain = With[{f = f}, ImplicitRegion[FunctionDomain[{f}, x], x]]
Out[2]=

In[3]:=

Plot[f, Element[x, domain], PlotTheme -> "Scientific",
Filling -> Axis, ImageSize -> 400]
Out[3]=
