GraphicMaths

Visualising maths

Parabolas

We have previously seen how a parabola is defined in terms of parametric equations or alternatively in Cartesian form. An alternative way to define a parabola is as a locus of points. Focus and directrix The locus defining a parabola depends on a focus and a directrix. The focus is a point. For a standard parabola, the focus is located on the x axis a distance $a$ from the origin, that is at the point (a, 0). Read more →