We are given that the focus (6, 0) lies on the x-axis, therefore x-axis is the axis of parabola. Also, the directrix is x = –6 i.e. x = –a and focus (6, 0) i.e. (a, 0). The equation of parabola is of the form $y^2$ = 4ax. The required equation of parabola is y2 = 4 × 6x ⇒ $y^2$ = 24x.