Finding quadratic function from two points and known max value

[Dave Britten]

Yup, right on the money. Just find b with "b = (x2 * sqrt((c - y1)/(c - y2)) + x1) / (sqrt((c - y1)/(c - y2)) + 1)", then find a with "a = (c - y1)/(x1 - b)^2". Then you've got your a, b, and c for the vertex form, and you can calculate y values. Thanks Nigel.