Lesson 1: Introduction to Inequalities
Duration of Days: 2
Lesson Objective
Students will be able to graph linear inequalities from slope-intercept form by identifying the correct boundary line (solid or dashed) and using test points to determine and shade the solution region.
How does the inequality symbol (< or >) tell us whether to use a dashed or solid line, and what does that line represent in our solution?
Why do we pick a "test point" like $(0,0)$ to check our work?
How does shading a help us show every possible (x,y) pair that works for the equation?
Solid Line
Dashed Line
Test Point
Intersection
HSA.CED.A.1: Create equations and inequalities in one variable and use them to solve problems.
HSA.REI.D.12: Graph the solutions to a linear inequality in two variables as a half-plane (excluding the boundary in the case of a strict inequality).
MP.4 Model with mathematics
MP.5 Use appropriate tools strategically
Description: This introductory lesson transitions students from graphing linear equations to graphing linear inequalities in two variables.
Purpose: The purpose of this lesson is to provide students with a visual and algebraic understanding of how constraints are represented in a two-dimensional space.
DOK Level: DOK 1 (Recall): Identifying the meaning of inequality symbols and the difference between solid and dashed lines.
DOK 2 (Skill/Concept): Graphing the boundary line and using a test point to determine the shaded region.
Students forget the difference between a dashed line and a solid line.
Incorrect shading of an area.
Forgetting to flip the inequality symbol when multiplying or dividing by a negative number.
Provide students with coordinate planes that include step-by-step checklists for the graphing process.
Exit Ticket
Formative Assessments