Lawrence Hall of Science
The Math Page: Topics in Pre Calculus: Quadratics
Here is a site that clearly and thoroughly explains quadratic functions, including graphing functions and solving equations using factoring. There are example problems solved, problems for the student to attempt, and answers to the...
Curated OER
Zona Land/the Function Institute/poly. Functions/graphs
Contains an applet that allows you to graph quadratic functions. An example is given and it lets you change the coefficient values.
Math Words
Mathwords: Quadratic Equation
The definition of a quadratic equation, followed by examples.