Khan Academy
Khan Academy: Completing the Square (Intermediate)
Solve quadratic equations of the form x^2+bx+c by completing the square.
CK-12 Foundation
Ck 12: 1.5 From Quadratics to Complex Numbers
This section introduces imaginary and complex numbers in the context of solutions to quadratic equations that don't have real-number solutions.
Help Algebra
Help algebra.com: Quadratic Equations
After defining a quadratic equation, this site shows you what the graphs of quadratics look like and how to use the graphs to determine the numbers of solutions to the quadratic. A brief explanation is included on how graphing...
Help Algebra
Help algebra.com: Quadratic Formula
This presentation of the quadratic equation includes a discussion on the discriminant and a derivation of the quadratic formula.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Quadratic Function (Changing Coefficients)
The Dr. gives information about a method for deciding how changing the coefficients of a quadratic function affects a graph. The page also leaves some questions for the reader to ponder.
ClassFlow
Class Flow: Quadratic Curves Algebra
[Free Registration/Login Required] In this flipchart, students interpret and graph quadratic curves. Students solve quadratic equations and then use the graphing features to graph the resultant quadratic curve.
ClassFlow
Class Flow: Solutions to Quadratics
[Free Registration/Login Required] Shows students how to solve for x within a quadratic function (no factoring) and identify the root(s) of the function.
ClassFlow
Class Flow: Solve by Completing the Square
[Free Registration/Login Required] This flipchart explores the steps for solving quadratics by completing the square.
Wyzant
Wyzant: Function Graphing Calculator
Students input a function in either y= of f(x)= form, and then the site from WyzAnt does the rest! A detailed graph is shown in less than a second. Students can change the window used to view the graph as well as whether to have...
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Quadratic Equations
Find a quick, concise explanation of the quadratic equations. An example is given and clearly explained.
ClassFlow
Class Flow: Factoring Trinomials
[Free Registration/Login Required] In this flipchart students are led on a discovery of the patterns found in factoring trinomials. They apply the patterns to factor.
Math Medics
S.o.s. Math: Quadratic Equations: Basic Definitions
This S.O.S. Math tutorial offers definitions and examples of quadratic equations and quadratic functions.
Purple Math
Purplemath: Special Factoring: Differences of Squares
Demonstrates how to use the formula for finding the differences of squares, and warns against trying to factor a sum of squares.
Purple Math
Purplemath: Solving Quadratic Equations by Factoring
Demonstrates how to solve quadratics using factoring (that is/the Zero-Product Property). Provides worked examples/and warnings about common mistakes.