If a 0 it opens downwards. If p is the distance from the vertex to the focus point called the focal length it is also the distance from the vertex to the directrix. The role of a.
As discussed earlier there are four standard forms of a parabola.
These three main forms that we graph parabolas from are called standard form intercept form and vertex form. Y2 -4ax An up facing parabola. Graph parabolas in all forms. Vertex form of a parabola The vertex form of a parabola is another form of the quadratic function f x ax2 bx c.