Graphing Linear Inequalities in Two Variables LESSON ESSENTIAL
QUESTION: How do you graph an inequality?
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WARMUP Complete Day 4 Warmup Problems
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Shade, Shade, Shade, Shade It Shade, Shade, Shade, Shade It
http://teachertube.com/viewVideo.php?video _id=121267
http://teachertube.com/viewVideo.php?video _id=121267
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Graphing Review Graph each line. a) y = x + 2b) x 2y = 6 Put
the equations into y=mx+b form to graph!
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Graphing a Linear Inequality Graphing a linear inequality is
very similar to graphing a linear equation.
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Graphing Inequalities Where do you think the points that are y
> x + 2 are located? Where do you think the points that are y
< x + 2 are located?
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Graphing Inequalities The line is the boundary of the two
regions. The blue region is the greater than (>) area and the
yellow region is the less than (
Steps to Graphing Linear Inequalities 1. Change the inequality
into slope-intercept form, y = mx + b. Graph the equation. 2. If
> or < then the line should be dashed. If > or < then
the line should be solid. 3. If y > mx+b or y > mx+b, shade
above the line. If y < mx+b or y < mx+b, shade below the
line. 4.To check that the shading is correct, pick a point in the
area and plug it into the inequality If TRUE, you shaded correct If
FALSE, you shaded incorrectly
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GRAPHING INEQUALITIES INEQUALITY SYMBOL TYPE OF LINE (dashed or
solid) WHERE TO SHADE (above or below line) < > dashed below
dashed above solidbelow solidabove
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GRAPHING INEQUALITIES SHADE UPSHADE BELOW SOLID LINE DASHED
LINE >
When dealing with slanted lines If it is > or then you shade
above If it is < or then you shade below the line
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Graph y - 3x + 2 on the coordinate plane. x y Boundary Line y =
- 3x + 2 m = - 3 b = 2 Test a point not on the line test (0,0) 0
-3(0) + 2 Not true!
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Graph y - 3x + 2 on the coordinate plane. x y Instead of
testing a point If in y = mx + b form... Shade up Shade down Solid
line Dashed line >
Graph on the coordinate plane. 3x - 4y > 12 - 3x - 4y > -
3x + 12 - 4 y < x - 3 m = b = - 3 Boundary Line x y Remember
that when you multiply or divide by a negative number..FLIP THE
INEQUALITY SIGN!!
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Example Example: 6 4 2 5 STEP 3 STEP 1 STEP 2
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Graphing a Linear Inequality Sketch a graph of y 3
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Graphing an Inequality in Two Variables Graph x < 2 Step 1:
Start by graphing the line x = 2 Now what points would give you
less than 2? Since it has to be x < 2 we shade everything to the
left of the line.
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HOMEWORK Complete the kuta worksheet
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Surfing with Inequalities Will the inequality surf splash over
our surfer? Decide if the shading of inequality (the surf) will
splash over the surfer. 2y > 10-x
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7.5 Practice Graph each inequality. Determine if the given
point is a solution. Do # 1-3 Check solution with your
neighbor
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Example Example: STEP 1 STEP 2 STEP 3
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CLASSWORK Complete the surfing with inequalities wsht Turn in
for a graded classwork assignment Be accurate with your graphing Be
careful when dividing by a negative #
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Absent Student Letter Write a letter to an absent student
explaining what an inequality is and how to graph a system of
inequalities?
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Graphing Review Use a graph to solve each system of equations.
a) y = x + 1 and y = -x + 3b) 2x y = 6 and y = x - 2 The solution
to a system of Equations is the POINT of INTERSECTION
