Parabolas - graphing and writing equations (2 of 3)

Показать описание

I introduce the two equations for parabolas: if x is squared then it opens up (positive) or down (negative) and if y is square then it opens right (positive) or left (negative). The distance (p) from the vertex to the focus and the vertex to the directrix are the same, it helps you find the "a" value: a=1/(4p). These parabolas can be shifted off of the origin (0, 0) with a transformation where (h, k) is going to be the vertex.

There are essentially two kinds of questions:
1. Given an equation, graph and/or find certain characteristics (vertex, focus, directrix, and axis of symmetry).
2. Given certain characteristics (vertex, focus, directrix, and axis of symmetry), write the equation of the parabola.