Answer
$3$
Work Step by Step
RECALL
$y=\log{x} \longleftrightarrow 10^y=x.$
Note that $1000=10^3$.
Thus, the given expression can be written as
$\log{10^3}.$
Let $y=\log{10^3}.$
Use the definition above to obtain
$y=\log{10^3} \longrightarrow 10^y=10^3.$
Use the rule "if $a^x=a^y$, then $x=y$" to obtain
$y=3.$
Therefore,
$\log{1000} = 3.$
