1. Objective: To graph horizontal and vertical lines.
Ch. 4.3
Objective:
To graph horizontal and vertical lines.

2. 4.2 Review Graph x + y = 5 x y -2 7 y -1 6 5 1 4 2 3 3 2 4 1 5 x 6 -15
Line is oblique 1 4 2 3 3 2 4 1 5 x 6 -1

3. Definition: Vertical Line
Vertical Line (x = a) where “a” is some number and “x” is always the value of “a”. Therefore, “y” can be any value. For example: x = 5 x y 5 1 -1
100

4. Graph.
x = -2
Line is Vertical x y y -2 -2 -2 -1 -2 -2 1 -2 2 x -2 3 -2 4
Any line in the
form x = k will
be vertical. -2 5

5. Definition: Horizontal Line
Horizontal Line (y = b) Where “b” is some number and “y” is always the value of “b”. Therefore, “x” can be any value. For example: y = 3 x y 3 2 5
100

6. Graph.
y = 3
Line is Horizontal x y y -2 3 -1 3 3 1 3 2 3 x 3 3 4 3
Any line in the
form y = k will
be horizontal. 5 3

7. Types of Lines Ax + By = C y = k x = k 3x - 2y = 5 y = -7 Oblique
Horizontal
Vertical
Equation
form
Ax + By = C
y = k
x = k
Example
3x - 2y = 5
y = -7
A = 3
Universal
constants
k = -7
B = -2
C = 5
A, B and C are integers (no fractions or decimals).
k represents a rational number.

8. Review x = k y = k Horizontal Line Vertical Line Perpendicular
to y-axis.
Perpendicular
to x-axis.

9. A) Graph x = -4 on a number line.
B) Graph x = -4 on a coordinate plane. y x

10. Finding Intercepts
x-intercept
= where the line crosses the x-axis
y-intercept
= where the line crosses the y-axis
Horizontal
Vertical
y = 2
x-int.= none
x = -1
x-int.= -1
y-int.= 2
y-int.= none y y x x

11. Find the x-intercept and y-intercept.
x = 5 or (5,0)
none 2)
none
3) x = -1
(-1,0)
none