Differentiate $f$ and find the domain of $f$ if $\displaystyle f(x)=\frac{3}{1+\ln{x}}$.

$f'(x)=$
Domain:

Note: Enter the domain as an interval or union of disjoint intervals, using 'U' for union, 'inf' and '-inf' for $\infty$ and $-\infty$ if necessary.