1. Vertex form (standard form) for the equation of a parabola y = a(x – h)2 + k x = a(y – k)2 + h Vertex: (h, k) Vertex: (h, k) Line of symmetry: x = h Line of symmetry: y = k
2. Graph x = 2y2 + 8y + 9 x = (2y2 + 8y ) + 9 x = 2(y2 + 4y + 4) + 9 - 8 x = 2(y+ 2)2 + 1 Vertex: (1, -2) Axis of symmetry: y = -2 Opens to the right
3. focus latus rectum directrix All points on the parabola are equidistant from the focus and the directrix.
4. y = a(x – h)2 + k focus 1 4a same distance directrix
5. y = a(x – h)2 + k focus latus rectum 1 a length = directrix