Answer
a. $g(6)=-9$
b. Domain:- $(-\infty,\infty)$. Range:- $\{-9\}$.
Work Step by Step
The given function is
$g(x)=-9$
a.
Substitute $x=6$ into the function.
$\Rightarrow g(6)=-9$
b.
This is a linear function in one variable.
Hence, all real number inputs will result in single number $-9$ as output.
The domain is $(-\infty,\infty)$.
and the range is $\{-9\}$.
