Revise how to recognise and determine the equation of a quadratic function from its graph. BBC Bitesize Scotland revision for SQA National 5 Maths.

If the graph of the quadratic function y = a x 2 + b x + c crosses the x -axis, the values of x at the crossing points are the roots or solutions of the equation a x 2 + b x + c = 0.

A good description of Least Squares Fit to Quadratic Data Part of a least squares fit involves solving three equations with three unknowns. Here is a description of using Excel's Solver to do this ...

Graph of a quadratic equation and its roots via the quadratic formula. Jacob Rus, CC BY-SA Equations and plots like these are part of algebra, but they’re not the whole story.