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Algebra 1
Graphing Equations
With a Table of Values
Objective
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Students will graph equations using a
table.
Students will graph horizontal and vertical
lines
Students will graph a variety of equations,
including linear, quadratic, and
exponential.
Cartesian Plane Basics
Vocabulary: Cartesian coordinate system: splitting the plane
into four quadrants and numbering:
Quadrant II
Y axis
Quadrant I
Origin
(0,0)
X Axis
Quadrant III
Quadrant IV
Cartesian Plane Basics
Vocabulary: Horizontal ACROSS
Vertical up/down
Quadrant II
Y axis
Quadrant I
Plot: (-3, 4)
Plot: (3, 4)
Plot: (-3, -4)
X Axis
Plot (3, -4)
Quadrant III
Quadrant IV
Cartesian Plane Basics
Vocabulary:
Independent variables: choose any thing legal,graph vertically
on y axis.
Dependent variables: maintain the relationship by following
the rule, graphed horizontally on x axis
Think of something numerical that depends on another value.
For instance: Soda costs $1
If I buy 3 cans it is $3.
Y = 3x is linear equation. HW I will give you the equation!
Make a T-chart and plot.
Cartesian Plane Basics
Vocabulary:
Graph: visual representation of a variable dependent on
another.
Y = cost
X = number of cans. Y = 3x is linear equation.
Make a T-chart and plot.
Choose x,
x y
FIND y from equation.
To Graph with a Table of Values
1.
2.
3.
4.
Choose at least 5 values (both positive and
negative) for x to plug into a table.
Plug those values one at a time into the
equation for x, and solve for y.
Plot those (x,y) ordered pairs on the
coordinate plane.
Follow the pattern of the graph to extend
the line through the coordinate plane.
Example #1
1. Choose values for x
2. Substitute the value
of x into the equation
y = 2x – 1
3. Simplify to
determine the
value of y
4. Write as an
ordered pair
y
(2,3)
x
(1,1)
(0, -1)
(x, y)
(0, - 1)
(1, 1)
(2, 3)
Comments
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How do you choose the value of x?
You can use any number for the value of
x…however, you can make your life easy by
choosing -1, 0, and 1, because you can do
mental math and they are easy to graph.
You choose a minimum of 5 numbers because
you need enough to see what the line will do.
Cartesian Plane Basics
1.) y = 3x + 5
T chart choose x find y.
x y
0 5
-1 2
1 8
2.) Plot & Connect points
3.) Extend line and locate x-int &
y-int
Cartesian Plane Basics
1.) y = 3x + 5
T chart choose x find y.
x y
0 5
-1 2
1 8
2.) Plot & Connect points
3.) Extend line, locate x-int & y-int:
x–int =( -1.7, 0)
y- int = (0, 5)
Example #2 – Horizontal Line
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Graph the equation y=2
In this instance there is no x-value. All
the y-values = 2
Example #2 (Continued)
y=2
y
y=2
x
Example #3 – Vertical Line
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
Graph the equation x = -3
In this instance there is no y-value. All
the x-values = -3
x
y
(x,y)
-3
-1
(-3,-1)
-3
0
(-3,0)
-3
1
(-3,1)
You try
Graph by plotting using a table of values:
Use -2, -1, 0, 1, and 2 for your x values
1.
Y = -3x + 1