Since the vertex of the parabola is at (0, 0) and focus is at (–2, 0).
∴ y = 0 ⇒ The axis of parabola is along x-axis
∴ The equation of the parabola is of the form y2 = – 4ax
The required equation of the parabola is y2 = – 4 × 2x ⇒ y2 = –8x.