Transcript 9.4 Graphing Linear Relations CORD Math Mrs. Spitz Fall 2006 Objectives:  Graph linear equations on a coordinate plane.

9.4 Graphing Linear Relations
CORD Math
Mrs. Spitz
Fall 2006
Objectives:
 Graph linear equations on a
coordinate plane.
Assignment
 pgs. 371-372 #5-46 all
 Mid-chapter Review pg. 373 #1-15 all
 Mid-chapter Test after this section.
Domain and Range
 If the domain of y = x -1
is the set of all real
numbers, then an infinite
number of ordered pairs
are solutions of the
equation. Suppose you
draw a line connecting
the points in a graph at
the right. The graph of
every solution of y = x –
1 lies on this line. The
coordinates of any point
on this line satisfy the
equation. Hence the line
is called the graph of y =
x-1
fx  = x-1
8
6
4
2
-15
-10
-5
5
-2
-4
-6
-8
10
Ex. 1: Determine whether each
equation is a linear equation.
1. 2x = 8 + y
An equivalent form of this equation is 2x – y = 8
Therefore, this is a linear equation with A = 2, B
= -1, and C = 8
2. 3x + y2 = 7
The exponent of all variables in a linear
equation must be 1. Therefore, this is not
a linear equation.
3. y = 7
An equivalent form of this equation is 0x + y
= 7. therefore, this is a linear equation
with A = 0, B = 1, and C = 7
Ex. 2: Draw the graph of y = 2x – 1
 An equivalent form
of this equation is
2x – y = 1. Thus,
it is a linear
equation. Set up a
table of values for
x and y. Then
graph the ordered
pairs and connect
the points with a
line.
x
2x - 1 y
(x, y)
-2
2(-2)-1
-5
(-2, -5)
-1
2(-1)-1
-3
(-1, -3)
0
2(0)-1
-1
(0, -1)
1
2(1)-1
1
(1, 1)
2
2(2)-1
3
(2, 3)
Ex. 2: Draw the graph of y = 2x – 1
x
2x - 1 y
(x, y)
-2
2(-2)-1
(-2, -5)
-5
hx  = 2x-1
8
6
4
-1
2(-1)-1
-3
(-1, -3)
0
2(0)-1
-1
(0, -1)
2
-15
-10
-5
5
-2
1
2(1)-1
1
(1, 1)
-4
-6
2
2(2)-1
3
(2, 3)
-8
Ex. 3: Draw the graph of 3x + 2y =4
3x  2 y  4
2 y  3x  4
3
y  x2
2
x
-3/2x + 2
y
(x, y)
-2
-3/2(2)+2
5
(-2, 5)
-1
3/2(-1)+2
7/2
(-1, 7/2)
0
3/2(0)+2
2
(0, 2)
1
3/2(1)+2
½
(1, ½)
2
3/2(2)+2
-1
(2, -1)
Ex. 3: Draw the graph of y = -3/2x +2
x
-3/2x + 2
y
(x, y)
q x  =
 
-3
2
x+2
8
-2
-3/2(2)+2
-1
3/2(-1)+2
5
7/2
(-2, 5)
6
4
(-1, 7/2)
2
0
3/2(0)+2
2
(0, 2)
-15
-10
-5
-2
1
3/2(1)+2
½
(1, ½)
-4
-6
2
3/2(2)+2
-1
(2, -1)
-8
Midchapter Review due tomorrow