Wolfram Research
Wolfram Math World: Quadratic Equation
This MathWorld site shows how to derive the quadratic formula.
Illustrative Mathematics
Illustrative Mathematics: F Bf, a Sse Building a General Quadratic Function
This task is a followup to the one called 'Building an explicit quadratic function.' For this one, students follow the same process with a general quadratic function. The operations take place in the opposite order and the goal is to...
CK-12 Foundation
Ck 12: Quadratic Formula and Complex Sums
[Free Registration/Login may be required to access all resource tools.] Know there is a complex number i such that i squared = -1, and every complex number has the form a + bi with a and b real.
CK-12 Foundation
Ck 12: Quadratic Formula and Complex Sums
[Free Registration/Login may be required to access all resource tools.] Represent complex numbers on the complex plane in rectangular and polar form (including real and imaginary numbers), and explain why the rectangular and polar forms...
Cuemath
Cuemath: Quadratic Functions
Explore the world of quadratic functions in this mini-lesson. Learn about the graphs of quadratic functions, quadratic functions formula, and other interesting facts. You can also try your hand at solving a few interesting practice...
Khan Academy
Khan Academy: Solve Quadratic Equations: Complex Solutions
Solve quadratic equations using the quadratic formula. Some of the equations have real solutions while others have complex solutions.
ClassFlow
Class Flow: Quadratic Formula
[Free Registration/Login Required] This flipchart teaches the Quadratic Formula and discriminant. It also uses models for when an object is thrown or dropped and has a velocity to find the distance the object traveled.
University of Illinois
University of Illinois: Quadratic Formula
This site from the University of Illinois offers an excellent simulation of the quadratic formula, where you can type in different values for a, b, and c, and then view the change in the answer for x.
Texas A&M University
Wtamu Virtual Math Lab: College Algebra: Quadratic Equations
A detailed tutorial that will guide you through various methods for solving quadratic equations: factoring, square root, completing the square, and quadratic formula. Follow step-by-step examples, view video problem-solving...
Khan Academy
Khan Academy: Solve Quadratic Equations Complex Solutions
Solve quadratic equations using the quadratic formula. Some of the equations have real solutions while others have complex solutions. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video...
Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Solving Quadratic Equations by Finding Square Roots
Twenty problems present a variety of problems working with various aspects of solving quadratic equations by finding the square roots. They are given with each step to the solution cleverly revealed one at a time. You can work each step...
Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Graphs of Quadratic Equations
Twenty-one problems present a variety of problems working with various aspects of solving and graphing quadratic equations. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the...
Integrated Publishing
Integrated Publishing: The Discriminant
A thorough investigation of what the discriminant is and how it is used. Contains examples and exercises, with answers on the page.
Illustrative Mathematics
Illustrative Mathematics: A Rei: Braking Distance
The purpose of this task is to give an application arising from a real-world situation, determining braking distance, in which a quadratic equation arises. In this scenario, it is natural to use a graphical method to find an approximate...
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...
Purple Math
Purplemath: Complex Numbers: Introduction
This website provides an in-depth lesson on complex numbers. You learn about simplifying, adding, and multiplying complex numbers by viewing example problems that are worked through step-by-step. Continue on to pages 2 and 3 which...
Stefan Warner and Steven R. Costenoble
Finite Mathematics & Applied Calculus: Polynomial Equations
The tutorial investigates how to solve polynomial equations. Students learn about the concept through class notes, examples, and practice problems. Topics include solving quadratic equations, factoring, and the quadratic formula.
Illustrative Mathematics
Illustrative Mathematics: F Bf Building a Quadratic Function From F(x) = X^2
This is the first of a series of tasks aiming at understanding the quadratic formula in a geometric way in terms of the graph of a quadratic function. Here the student works with an explicit function and studies the impact of additive...
Purple Math
Purplemath: Completing the Square: Deriving the Vertex Formula
This resource describes in steps how to derive the vertex formula.
CK-12 Foundation
Ck 12: Algebra: Solving Quadratic Equations Study Guide
This comprehensive study guide highlights the main terms and formulas needed to review solving quadratic equations. Examples are included.
CK-12 Foundation
Ck 12: Algebra: Use Graphs to Solve Quadratic Equations
[Free Registration/Login may be required to access all resource tools.] Determine the number of solutions to a quadratic equation and find such solutions by graphing.
CK-12 Foundation
Ck 12: Algebra: Comparing Methods for Solving Quadratics
[Free Registration/Login may be required to access all resource tools.] Select the best method to solve-real world quadratic equation problems.
CK-12 Foundation
Ck 12: Algebra: Factorization of Quadratic Expressions
[Free Registration/Login may be required to access all resource tools.] Factor quadratic polynomial expressions of the form ax^2 + bx + c.
Math Is Fun
Math Is Fun: Real World Examples of Quadratic Equations
Provides examples of how quadratic equations can be used in real-world scenarios, and the different methods used to solve them.