Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: La Ecuacion De Segundo Grado
In Spanish. In this interactive activity you can learn to recognize quadratic equations, solve quadratic equations with one unknown in graphical and numerical form, and solve practical problems.
Math Is Fun
Math Is Fun: Algebra: Graphing Quadratic Equations
Explains how to graph quadratic equations and how to find the quadratic equation when given just the graph. Includes ten practice questions.