For a parabola $y^2 = 4ax$ ,we can draw $2$ tangents from any point.If the point is outside of parabola then obviously we can draw $2$ tangents. If the point is on the parabola then the two tangents will coincide and it is easy to draw that picture. I know that if the point is inside the parabola then the tangents are imaginary.
But What does it means that the tangents are imaginary ? And I don't know how it will draw?