# Lesson Plan: Solving Quadratic Equations Using Graphs Mathematics • Third Year of Preparatory School

This lesson plan includes the objectives, prerequisites, and exclusions of the lesson teaching students how to graph a quadratic function of the form 𝑓(𝑥) = 𝑎𝑥² + 𝑏𝑥 + 𝑐, in order to solve the equation 𝑓(𝑥) = 0.

#### Objectives

Students will be able to

- understand that, for a quadratic function of the form
- the solutions to the equation occur where the graph intersects the ,

- find the solutions to the equation
- when given the graph of ,
- when points of the form that lie on the graph are specified,
- by plotting the graph of over a specified interval.

#### Prerequisites

Students should already be familiar with

- drawing graphs from tables of values,
- graphing quadratic functions,
- the fact that the equation may have one, two, or no solutions.

#### Exclusions

Students will not cover

- graphs of linear functions,
- graphs of cubic functions (or higher),
- solving quadratic equations by factorization,
- solving quadratic equations using the quadratic formula,
- quadratic functions with fractional, decimal, or irrational coefficients.