The graph of the quadratic function y = a x 2 + b x + c has a minimum turning point when a> 0 and a maximum turning point when a a <0. The turning point lies on the line of symmetry.

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.