Graphing Systems of Linear Inequalities (Day 1 of 2)
Lesson 3 of 5
Objective: SWBAT graph linear systems of inequalities on a number line.
Students will complete the Do Now while the graded Exit Cards from our last class are passed back. Once they have completed the task, I will ask volunteers to go to the board and sketch their responses. I will ask the class to identify a way that each graph can be checked given their similar nature.
Next a student will read the objective, "SWBAT graph linear systems of inequalities on a coordinate plane."
My students learned a variety of methods to solve systems of equations in our last unit. To give students the idea that we will be building on their prior knowledge, I will ask students to make a prediction about what we will learn in this unit based on today's objective.
Guided Notes + Practice
A note about Slide 3: Since today's lesson mimics our last class, I will ask students to graph and shade the first inequality. I then will model the graphing of the second inequality. I will graph this second example with a different color so that students can clearly distinguish between the two.
As we work on graphing the inequalities, I will encourage students to pick 5 test points and input the coordinates into the table in the (x, y) column. I will work with the class to make sure that we pick five points that are in different locations in and out of the solution set. As a whole group we will go through the table, placing an "x" inside the cell if the corresponding test point is a solution for that particular inequality. We will then complete the last column of the table, writing the word YES if their are two "X" symbols in that row, and NO if there are not.
Using the information in our table, I will refer back to the graph. We will shade the regions where both inequalities overlap with a third color. Some students have a hard time visualizing this on the graph, so they prefer to use the table Yes/No method.