Parabolas

A parabola is a curve that is equidistant from the directrix and focus. The general equation of a vertical parabola is (x-h)^2=4c(y-k). For a horizontal parabola the general equation is (y-k)^2=4c(x-h). To graph a parabola you need to find the vertex, focus, directrix and axis of symmetry. For a vertical parabola to find the vertex you find (h,k) the focus is (h, k+c), the directrix is y=k-c and the axis of symmetry is x=h. For a horizontal parabola the vertex is also (h, k), the focus is (h+c,k) the directrix is x=h-c and the axis of symmetry is y=k. Here is an example of a parabola.