Answer
$f(x)=\dfrac{1}{6}(x+3)(x-1)(x-4)$
Work Step by Step
Here, we have $f(x)=a (x+3)(x-1)(x-4)$
When $x=0$, then we have $2=a (0+3)(0-1)(0-4)$
or, $12a=2$
This gives: $a=\dfrac{1}{6}$
Thus, we have $f(x)=\dfrac{1}{6}(x+3)(x-1)(x-4)$