Cubic graphs have “point symmetry,” which means there’s a special point on the graph of every cubic function where, if a line passes through that point and intersects the cubic anywhere else, it ...

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.

Michael Weiss, Solving and Graphing Quadratics with Symmetry and Transformations, The Mathematics Teacher, Vol. 110, No. 5 (December 2016/January 2017), pp. 394-397 ...

In this example: 4 ÷ 2 = 2. The two solutions to the quadratic equation will be the axis of symmetry plus or minus an unknown amount, which we’ll call u. In this example: r = 2 – u and s = 2 + u ...

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 ...