1. Mon, 11/13 SWBAT… graph lines on a TI-83 Agenda 1. WU - (10 min) 2. Graphing calculator activity (35 min) Warm-Up: 1. Turn in your test corrections in the blue folder 2. Take out Get Ready for Chapter 4 (leave it on your desk) 3. Write your HW in your planner for the week HW: Get Ready for Chapter 4

2. Write the calculator number on your worksheet and your names (you will be working with the person next to you.)

3. SWBAT… find x- and y-intercepts algebraically and graphically. Agenda 1. Warm-Up (10 min) 2. Notes on x- and y intercepts (15 min) 3. OYO problems (10 min) Warm-Up: 1. Graph 2x – y = -1 using a table of values 2. Circle and label the point where the line crosses the x-axis 3. Circle and label the point where the line crosses the y-axis HW#1: x- and y-intercepts Thurs, 11/4

4. x y = 2x + 1

5. New unit - what will we be learning (5 weeks) 1. x-and y-intercepts (solving and interpreting) 2. Slope (solving and interpreting) 3. Graphing and writing equations of lines 1. Slope-intercept form  y = mx + b 2. Point slope form  (y – y 1 ) = m(x = x 1 ) 3. Standard forms  Ax + By = C 4. Parallel and perpendicular lines 5. Lines of best fit We will do an Infinity Teachers traveling project at the conclusion of this unit.

6. What does it mean to INTERCEPT a pass in football? The path of the defender crosses the path of the thrown football.

7. x- and y-intercepts The x-intercept of a line is the point at which the line crosses the x-axis. ( i.e. where the y value equals 0 ) x-intercept = ( x, 0 ) The y-intercept of a line is the point at which the line crosses the y-axis. ( i.e. where the x value equals 0 ) y-intercept = ( 0, y ) Also called the Zero-Zero Method

8. Directions: Find the x- and y-intercepts Ex1: 2x – y = -1 x-int. y = 0 2x – y = -1 2x – 0 = -1 2x = -1 x = -1/2 (-1/2, 0) y-int. x = 0 2x – y = -1 2(0) – y = -1 -y = -1 y = 1 (0, 1)

9. Now go back and look at your WU line Q: What was the x-intercept graphically? A: (-1/2, 0) Q: What was the x-intercept algebraically? A: (-1/2, 0) Q: What was the y-intercept graphically? A: (0, 1) Q: What was the y-intercept algebraically? A: (0, 1) AHA!!! Don’t you love it when math makes sense!

10. Graphing linear equations To graph a linear equation you can use: 1.) Table of values (last week and WU) 2.) Intercepts (right now!) 3.) Slope intercept form (y = mx + b) (next project)

11. 2x – y = -1 Graph 2x – y = -1 using x- and y- intercepts To graph lines using x- and y- intercepts: Step 1: Find the x- and y- intercepts. x-int: (-1/2, 0) y-int: (0, 1) Step 2: Plot the two points. Step 3: Connect the points, extend the line, arrows at end, label the line. x 2x – y = -1

12. x-int. y = 0 3x – 5y = 9 3x – 5(0) = 9 3x = 9 x = 3; (3, 0) y-int. x = 0 3x – 5y = 9 3(0) – 5y = 9 -5y = 9 y = - ; (0, - ) Graph 3x – 5y = 9 using x- and y-intercepts

13. To graph lines using x- and y- intercepts: Step 1: Find the x- and y- intercepts. x-int: (3, 0) y-int: (0, -1.8) Step 2: Plot the two points. Step 3: Connect the points, extend the line, arrows at end, label the line. x 3x – 5y = 9

14. What are the x- and y-intercepts? The x-intercept is where the graph crosses the x-axis. The y-coordinate is always 0. The y-intercept is where the graph crosses the y-axis. The x-coordinate is always 0. (2, 0) (0, -6) x y

15. What are the x- and y-intercepts? xy -3 -20 1 02 13 x-int: (-2, 0) y-int: (0, 2)

16. Solve for y: Ax + By = C When an equation is given in the form Ax + By = C, the slope is:

17. x-int. Let y = 0 y = 3 0 = 3 0 = 3??? No! There is no x-intercept. None What type of lines have no x-intercept? Horizontal! y-int. Let x = 0 y = 3 (y is already solve for) (0, 3) Find the x- and y-intercepts of y = 3 ***Special case*** y = 3

18. x-int. Let y = 0 x = -4 (x is already solved for) (-4, 0) y-int. Let x = 0 x = -4 0 = -4??? No, there is no y-intercept. None What type of lines have no y-intercept? Vertical! Find the x- and y-intercepts of x = -4 ***Special case*** x = -4

19. What is the x-intercept of 3x – 4y = 24? 1. (-6, 0) 2. (8, 0) 3. (0, -4) 4. (8, -6)

20. What is the y-intercept of -x + 2y = 8? 1. (-1, 0) 2. (-8, 0) 3. (0, 2) 4. (0, 4)

21. What is the x-intercept of y = 1? (Hint: Draw this graph) 1. (1, 0) 2. (-1, 0) 3. (0, 1) 4. None

22. What is the y-intercept of y = 1? (Hint: Draw this graph) 1. (1, 0) 2. (-1, 0) 3. (0, 1) 4. None

23. What is the y-intercept of x = 3? (Hint: Draw this graph ) 1. (3, 0) 2. (-3, 0) 3. (0, 3) 4. None

24. HW#1 Answers 1. x-int = (3, 0) y-int = (0, 5) 2. x-int = (7, 0) y-int = (0, -2) 3. x-int = (0, 0) y-int = (0, 0)

25. SWBAT… find x- and y-intercepts graphically and algebraically Agenda 1. Warm-Up (10 min) 2. Notes / practice on x and y intercepts (30 min) Warm-Up: Find the x- and y-intercepts: -3x + 5y = 9 HW#2: x-and y-intercepts Fri, 11/5