The following equation for a quadratic function:
is written in “Vertex Form”.
(h, k) – Coordinates of the Vertex of the Parabola
x – Location of the Axis of Symmetry
a – indicates the width and direction (up or down) of the Parabola
When a is positive, the parabola opens upwards. When a is negative, the parabola opens downwards. As a increases its distance from zero, the parabola becomes narrower.
-The graph moves |h| units left if h is negative or |h| units right if h is positive.
-The graph moves |k| units up if k is positive, or |k| units down if k is negative.
Below is a graph of a quadratic function in vertex form: