The parabola whose equation is y 2 = 12x has directrix of:

x = 3

x = - 3

y = 3

y = - 3

The parabola whose equation is y 2 = 12x has directrix of:

x = 3

x = - 3

y = 3

y = - 3

The directrix is:

x=-3

One way of solving is to assign values for x and y:

x y

0 0

1 3.46

1 - 3.46

2 4.9

2 - 4.9

When graphed, the solution is:

Direction: Opens RightVertex: (0,0) (0,0) Focus: (3,0) (3,0) Axis of Symmetry: y=0 Directrix: x=-3