How do we find a quadratic function given its graph? [ATTACH=full]3973[/ATTACH]

use general formula for parabola: y=ax^2+bx+c or vertex form formula for parabola: y=(x-h)^2+k choose at least 3 points from the graph, plug in formula above, set the system and solve for a, b, and c (if you use general formula) or sole for h and k if you use vertex form formula hint: take a lose look on a graph and decide which formula is better to use