Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Quadratic Functions
Twenty problems present a variety of problems working with various aspects of quadratic functions. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the "View...
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Definition of Quadratic Function
Dr. Math briefly defines a quadratic function.