Download 3.1 Graphing Linear Equations

3.1 Graphing Linear
Equations
10/10/16
CC State Standards
• For a function that models a relationship between two quantities ,
interpret key features of graphs and tables.
New Vocabulary
• Linear equation
• Standard Form
• Constant
• X – axis
• Y - axis
• X – Intercept
• Y - Intercept
Definitions
• Linear equations – An equation that forms a line when it is graphed.
• Standard form – The standard form of a linear equation is Ax + By = C.
• Constant – In a linear equation, C is called a constant, or a real
number. Ax and By are variable terms.
Definitions
• X – Axis – The horizontal number line on a coordinate plane.
• Y – Axis – The vertical number line on a coordinate plane.
• X – Intercept –The x-coordinate of the point at which the graph of an
equation crosses the x – axis.
• Y – Intercept – The y-coordinate of the point at which the graph
crosses the y-axis
Standard Form of a Linear Equation
• Ax + By = C
• IE. 3x + y = 4
• A = 3 , B = 1 , C = 4. This is a linear
equation because it is written in
standard form
• Determine whether each equation
is a linear equation. Write the
equation in standard form.
• x=y–5
• 6x – xy = 4
• 5x + y2 = 25
• 8 + y = 4x
Graph each equation by using the X and Y
intercepts
• y=4+x
• To find the y intercept, let x = 0.
• To find the x-intercept, let y = 0. • y = 4 + 0
• 0 = 4 + x then isolate the variable • y = 4
• -4 -4
• This means the graph intersects
the y-axis at (0,4).
• -4 = x This means the graph
intersects the x-axis at (-4,0)
• Plot these points then draw a
line through them.
Graph each equation by using the X and Y
intercepts
• 2x – 5y = 1
• y = 4 + 2x
Graph each equation by making a table.
Y = 2x
X
-2
-1
0
1
y = 2x
Y
(X,Y)
Graph each equation by making a table.
6x – 3y = - 3
Get “y” by itself
X
-2
-1
0
1
Y
(X,Y)
TOTD
• Graph each equation by making
a table.
Y = 3x
X
-2
-1
0
1
2
Y = 3x
Y XY
• Plot the two points then draw a
line through them.