#### Answer

$-3, -1, 1, 3$

#### Work Step by Step

RECALL:
The possible rational zeros of a polynomial function is given by $\dfrac{p}{q}$ where:
$p$ = factor of the constant term
$q$ = factor of the leading coefficient
The given polynomial function has:
constant term = $3$
leading coefficient = $1$
The factors of the constant term are: $\pm1, \pm3$
The factors of the leading coefficient are: $\pm 1$
Thus, the possible rational zeros of the given polynomial function are:
$\pm 1, \pm 3$