CK-12 Foundation
Ck 12: Algebra: Completing the Square
[Free Registration/Login may be required to access all resource tools.] Learn how to complete the square in order to solve quadratic equations.
CK-12 Foundation
Ck 12: Algebra: Quadratic Formula
[Free Registration/Login may be required to access all resource tools.] This lesson covers deriving the quadratic formula and using it to solve any quadratic equation.
Cool Math
Coolmath: The Quadratic Formula
Reference material and practice problems using the quadratic formula.
Khan Academy
Khan Academy: Completing the Square
Solve quadratic equations of the form ax^2+bx+c by completing the square.
Other
Nearpod: Quadratic Equations: The Quadratic Formula
In this instructional activity, students will solve quadratic equations using the quadratic formula.
Other
Nearpod: Quadratic Equations: Completing the Square
In this instructional activity on completing the square, students explore the connection between area models and perfect square trinomials. They also learn how to complete the square to transform a quadratic equation into vertex form.
Help Algebra
Help algebra.com: Quadratic Equations
This article gives a definition of quadratic equations, then demonstrates how to solve them. Factoring, completing the square and the quadratic formula are the methods described. The examples are accompanied by lists of steps for solving...
Help Algebra
Help algebra.com: Completing the Square
The process of completing the square is presented with a detailed description of the process and an example to show the work step by step. An example with a non-integer leading coefficient is also included.
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.
Help Algebra
Helpalgebra: Geometrical Approach to Completing Square
Using geometrical diagrams, the process of completing the square is demonstrated. Applying this visual approach will help to see why the process works.
Math Notes and Math Tests
Pre Calculus Notes: The "Qf" Method for Factoring Quadratics [Pdf]
Learners examine the quadratic formula method for factoring quadratics. Examples with detailed solutions are included.
Purple Math
Purplemath: Completing the Square: Deriving the Vertex Formula
This resource describes in steps how to derive the vertex formula.
ClassFlow
Class Flow: Solve by Completing the Square
[Free Registration/Login Required] This flipchart explores the steps for solving quadratics by completing the square.
Free Math Help
Free Math Help: The Quadratic Formula
The lesson teaches students about the quadratic formula. The resource includes detailed explanations about how to use the quadratic formula.
Wyzant
Wyzant: Solve by Completing the Square
The practice sheet reviews how to solve equations by completing the square. The resource consists of an answer sheet and example problem.
Wyzant
Wyzant: Solving Using the Quadratic Formula Worksheet
The practice sheet reviews how to solve equations using the quadratic formula. The resource consists of 20 questions with answers available.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Complete the Square
Find a quick, concise explanation of how to complete the square. An example is given and explained to illustrate the method.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Solving Quadratic Equations With Square Roots
Find a quick, concise explanation for how to solve quadratic equations using square roots. An example is given and clearly explained.
Stanford University
Quadratic Formula/explanation
A step-by-step explanation of how the quadratic formula is obtained from the general form quadratic polynomial.
Other
Completing the Square to Get a Quadratic Function Into Standard Form
This site shows students how to put a quadratic function into standard form by completing the square.
Purple Math
Purplemath: The Quadratic Formula Explained
An excellent discussion on solving quadratic formulas, accompanied by numerous examples.
Math Words
Mathwords: Quadratic Equation
The definition of a quadratic equation, followed by examples.