1. Slope Graphing Writing Equations of lines Parallel and perpendiclar

2. Lines in the plane I. Slope Steepness of a line where x1 ≠ x2, that would be a vertical line

3. If the denominator of the slope is 0 then the slope is undefined and you have a vertical line
+slope - slope 0 slope no slope
A line with a positive slope rises from left to right
A line with a negative slope falls from left to right
A line with a slope of zero is horizontal
A line with an undefined slope is vertical

4. Examples: Find the slope of the line passing through 1
Examples: Find the slope of the line passing through 1. (-2, -4) and (3, -1) (3, -4), (1, 6) 3. (2, -1) , (2, 5)

5. 4. Without graphing, tell whether the line through the given points rises, falls, is horizontal, or is vertical. ( 1, -2) , (3, -2)

6. 5. Tell which line is steeper
5. Tell which line is steeper. Line 1: through (1, -4) and (5, 2) Line 2: through (-2, -5) and (1, -2)

7. 6. Tell whether the lines through the given points are parallel, perpendicular,
or neither.
(1, -2), (3, -2) and (-5, 4), (0, 4)
b) (-2, -2), (4, 1) and (-3, -3), (1, 5)

8. Slope-intercept form ~ y = mx + b
II. Writing Linear Equations
Slope-intercept form ~ y = mx + b
Point-slope form ~ y – y1 = m (x – x1)
Two points ~ m = y2 – y1
x2 – x1

9. Slope- Intercept y = mx + b. Slope- intercept form
Slope- Intercept y = mx + b **Slope- intercept form ** m = slope b = y-intercept

10. Standard Form. Standard Form
Standard Form ** Standard Form** Ax + By = C Where A and B are not both zero slope = y-int =

11. 7. Write an equation of the line shown.
8. Write an equation of a line that passes through
(-3, 4) and has a slope of .

12. 9. Write an equation of a line that passes through
(-2, -1) and (3, 4).

13. Write an equation of a line that passes
through (2, -3) and is perpendicular
to y = 2x + 3.

14. 11. Write an equation of a line that passes through(2, -3) and is parallel to y = 2x + 3.

15. QUICK GRAPHS OF LINEAR EQUATIONS Terminology a) slope-intercept form b) standard form c) y-intercept = point where graph crosses the y-axis (let x = 0 and solve for y) d) x-intercept= point where graph crosses the x-axis (let y = 0 and solve for x)

16. To quick graph do the following: 1) Write equation in slope-intercept form 2) Find the y-intercept and plot the point 3) Find the slope and use it to plot a second point 4) Draw a line through the two points

17. Ex12.: Graph y =

18. To quick graph do the following: 1) Write equation in standard form 2) Find the y-intercept and plot the point 3) Find the slope and use it to plot a second point 4) Draw a line through the two points

19. Ex 13.: Graph 2x + 3y = 12

20. Graphing Horizontal and Vertical Lines a) horizontal lines are in the form: y = # b) vertical lines are in the form: x = #

21. 14. Graph x = -2

22. 15. Graph y = 5

23. To quick graph using a table do the following: 1) pick 3 x values 2) plug the x into the equation and solve for y 3) plot those points 4) Draw a line through the points

24. 16. Graph y = -2x + 3
x y

25. To graph an inequality
Graph the equation by the method of
your choice
Pick a point and check in the equation
If it is true shade that direction
If it is false shade the opposite side of the
equation

26. 17. Graph y < -2x + 3