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Graphing Linear Inequalities

HSA-REI.D.12
Answer Keys Here

Aligned To Common Core Standard:

High School - HSA-REI.D.12

How to Graph Linear Inequalities - By now you must have understood the importance of graphing equations. Linear equalities or linear inequalities, both types can be plotted on a graph. But plotting needs comprehension and comprehension needs understanding. So, to start with the basics, let's learn what are Linear Inequalities. Linear Inequalities also entails a linear function while being an inequality. A linear inequality contains the symbols of inequality. The thing about Inequalities is that they can represent inequal data on a graph. Let's find out how you can graph Linear Inequalities. To appropriately graph a linear inequality, plot the "equals" line on the graph first, then shade in the correct area. You can follow the following three steps: - Make sure to rearrange the equation, leaving the y-variable on the left and everything else on the right side of the equation. - Now consider plotting 'y=' line; make it a definite line for y≤ or y≥, and a dashed line for y< or y>. - Now color or shade above the line for representing a "greater than" (y> or y≥) or below the line for a "less than" (y< or y≤). These worksheets and lessons help students make polts of linear inequalities in a half plane setting.

Printable Worksheets And Lessons






Homework Sheets

Hopefully the shading works out for you.

  • Homework 1 - The graph of y < -5 is a horizontal line. Every y-value is -5, including the y-intercept. Start by graphing the line y = -5.
  • Homework 2 - The slope-intercept form of a linear is like the slope intercept form of an equation (y = mx +b), but with an inequality symbol instead of an equals sign.
  • Homework 3 - The slope-intercept form of a linear is like the same form of an equation (y = mx +b), but with an inequality symbol instead of an equals sign.



Practice Worksheets

I found that black and white copies come out better with this color scheme, I'm not sure why.

  • Practice 1 - If the inequality uses the symbol ≥, so be sure to draw a solid line.
  • Practice 2 - Finally, figure out which region to shade. You could remember that when inequalities start with y > or y ≥, you should shade above the line.
  • Practice 3 - Graph all the inequalities below.



Math Skill Quizzes

Flat graphs, then tilted graphs, ending with more flat graphs.

  • Quiz 1 - You could remember it as, if you are lesser than something, the shade is below you. If you are greater than a value, the shade is above you.
  • Quiz 2 - Finally, figure out which region to shade. You could remember that when inequalities start with y > or y ≥ , you should shade above the line.
  • Quiz 3 - Graph this inequality completely with shading: y < 5


Why Do We Graph Linear Inequalities at All?

In many cases this skill is presented to students in a matter of fact manner. Truly understanding why this skill matters helps students understand where and when to apply it. When you perform this skill you will treat it like any other linear function that you place on a coordinate system. The difference is that you are just not plotting out a line but shading an area from the line that satisfies the inequality. What that means is that we are entirely sure where the answer lies in the coordinate system, but we are certain where it could be. Think of it like a search map that you see in all those cheesy action movies. We know that the suspect will be found in the area. That is the same thing as the solution to our inequality, we know that the answer lies in here. While this is not an exact science it is very helpful in narrowing down where the solution lies. When you begin to work on more complex projects you will see situations where you have multiple related inequalities. When you put several of these solutions together you can begin to pattern emerge that really tightens down your final answer.