The equation of a parabolacan be written in two basic forms: Form 1: y = a( x – h) 2 +k. Form 2: x = a( y – k) 2 +h. In Form 1, the parabolaopens vertically. (It opens in the “ y” direction.) If a > 0, it opens upward. Refer to Figure 1(a). If a < 0, it opens downward. The distance from the vertex to the focus and from the vertex to the directrix line are the same. Parabola - CliffsNotes Was this helpful? Equations of a parabolas graph Cheat Sheet - Hacking Math Apr 14, 2015Equations of a parabolas graph Cheat Sheet. 14 April 2015. Equations of a Parabola: Vertex at (0,0); Focus on Axis; a > 0. Equations of a Parabola: Vertex at (h,k); Axis of Symmetry Parallel to a Coordinate Axis; a > 0. Twitter Facebook Google+.Author: Rick H Math formulas and cheat sheet for conic sections To create cheat sheet first you need to select formulas which you want to include in it. To select formula click at picture next to formula. You can choose formulas from different pages.