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.

All quadratic functions have the same type of curved graphs with a line of symmetry. The graph of the quadratic function y = a x 2 + b x + c is a smooth curve with one turning point.