Download L5 Writing Equations m=0, m= undefined

Integrated Algebra
NOTES
Special Equations
m= o, m= undefined
Name
When writing equations for lines with slopes that are either 0 or undefined, it will be
easy if you have memorized the type of line with those slopes.
Remember the 4 different types of slopes:
Negative
Positive
0
Undefined

Equations for lines with positive and negative slopes are found using the method
from the last lesson.

The lines with slopes of 0 and undefined are more easily determined by the
consistent orientation of the line; there is no steep or shallow….it is either
vertical or horizontal.
VERTICAL line - slope is undefined;
x = -3
equation is always “x = ____”
HORIZONTAL line - slope is 0;
equation is always “y = ____”
y=2
Integrated Algebra
Use the coordinate of a point on the line to determine the equation.
EX: Write the equation of the line through (4,1) with an undefined slope:
EX:

Since the slope is undefined, you know it will
be a vertical line.

The equation for all vertical lines will be x = ____

It has to go through (4,1) so plot (4,1) and
draw a vertical line through it.

What are the x values for all points?

Equation is x = 4
Write the equation of the line through (-3, 2) with an undefined slope:

Since the slope is undefined, you know it will
be a vertical line.

The equation for all vertical lines will be x = ____

It has to go through (-3, 2) so plot (-3, 2) and
draw a vertical line through it.

What are the x values for all points?

Equation is x = -3
TRY: Write the equation of the line through (2, -1) with an undefined slope:

Since the slope is undefined, you know it will
be a _______________line.

The equation for all vertical lines will be _________

It has to go through (
) so plot (
draw a vertical line through it.

What are the x values for all points?

Equation is __________
) and
Integrated Algebra
EX:
EX:
TRY:
Write the equation of the line through (3, 1) with m = 0:

Since the slope is 0, you know it will
be a horizontal line.

The equation for all horizontal lines will be y = ____

It has to go through (3, 1) so plot (3, 1) and
draw a horizontal line through it.

What are the y values for all points?

Equation is y = 1
Write the equation of the line through (-2, -3) with m = 0:

Since the slope is 0, you know it will
be a horizontal line.

The equation for all horizontal lines will be y = ____

It has to go through (-2, -3) so plot (-2, -3) and
draw a horizontal line through it.

What are the y values for all points?

Equation is y = -3
Write the equation of the line through (4, 2) with m = 0:

Since the slope is 0, you know it will
be a __________ line.

The equation for all horizontal lines will be _______

It has to go through (
) so plot (
draw a horizontal line through it.

What are the y values for all points?

Equation is ________
) and
Integrated Algebra
 Sketching the line may help you with the equation.
 Try to remember that the equation of the line is the same value as the appropriate
coordinate used in the equation.
EX: Write an equation through (-4, 5) with slope of 0
Think: slope of 0 means horizontal line which means y = _____
For that point, y is 5 so the equation is: y = 5
EX: Write an equation through (7, -1) with an undefined slope.
Think: slope is undefined so it is a vertical line which means x = ______
For that point, x is 7 so the equation is: x = 7
TRY :
Write an equation through:
Sketch if it helps.
1) (4, -3) with m = 0
2) (-5, -1) with an undefined slope
3) (3, 2) with an undefined slope
4) (-1, 4) with m = 0
Integrated Algebra
Homework Special lines and their equations
Name
Sketch each equation on the graph.
1. y = 2
2. x = -1
3. y = -3
4. x = 2
5. x = -3
6. y = -1
On the graph provided: a) sketch the line
7. Through ( 3, 1) with m = 0
b) write the equation of the line
8. Through (-2, 2) with m undefined
Integrated Algebra
9. Through the origin with m = 0
10. Through (-2, 3) with m = 0
11. Through (3, 1) with m undefined
12. Through origin with m undefined
Answer each question below.
13. a)All equations that are “x = ___” will be what kind of line?
b) What will the slope be for all those lines?
14. a) All equations that are “y = ___” will be what kind of line?
b) What will the slope of all those lines be?
Answer each question with vertical or horizontal .
15. The line y = 3 will be _________________.
16. The line y = -5 will be __________________.
17. The line x = 1 will be _________________.
18. The line x = -2 will be ___________________.
_______________
_______________
_______________
_______________