09 - The Quadratic Formula Explained, Part 1 (Practice Problems & Solutions)

View more lessons at http://www.MathAndScience.com. In this lesson, you will learn what the quadratic formula is, how to use it, and why it is important to solve quadratic equations in algebra. First, we will derive the quadratic formula using the completing the square method. Next, we will solve numerous quadratic equations using the quadratic formula and check the answers.