Answer
domain: $(-\infty,3)$
Work Step by Step
The restriction for the domain of a logarithmic function:
the argument must be positive
Domain: all x for which $3-x>0$
$3-x>0\qquad/+x$
$3>x$
(x can be any number less than 3)
In interval notation,
domain: $(-\infty,3)$
