There are multiple ways of solving quadratic equations, and in this lecture we'll learn how to solve them by graphing. We will use the standard form of a quadratic equation to graph it, so the first step is to make sure your equation is in the standard form. The solutions of a quadratic equation are also called roots, or the x-intercepts. There could be 0, 1, or 2 real solutions. Sometimes it's hard to get an exact solution, so we often use estimation. If a root is not an integer, estimate the root by stating the two consecutive integers it lies between.
A quadratic equation has 2 real roots if its graph has 2 x-intercepts, one real root if it has 1 x-intercept (in this case, the graph is tangent to the x axis), and no real roots if it has no x-intercepts.
If a root is not an integer, estimate the root by stating the two consecutive integers it lies between.
A real number is a zero of the quadratic function f(x) if and only if it is a root of the equation f(x) = 0.
Solving Quadratic Equations by Graphing
Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.