Answer
F(p,0)
x=-p
(3,0)
$x=-3$
Work Step by Step
$y^{2}=4px$ is the equation for a parabola opening horizontally.
We can observe from the example equation $y^{2}=12x$ that the coefficient of y is 12
To find the p value set $12=4p$
(This will allow you to find the focus and directrix of a parabola centered at the origin)
Now solve for p
$3=p$
To find the focus use the focus coordinates (p,0)
Substitute:
The focus is at (3,0)
To find the directrix use the directrix formula $x=-p$
Substitute:
The directrix is $x=-3$
Keep in mind these formulas and coordinates are for finding the directrix and focus when the parabola's vertex is at (0,0).