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Finding Slope and Writing Equations in Slope-intercept Form. Standard: A.CED.2 (Algebra. Creating Equations.). Essential Questions. How do I find slope using the slope formula? How do I rewrite an equation in slope-intercept form? How do I identify the slope and the y-intercept?.
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Finding Slope and Writing Equations in Slope-intercept Form Standard: A.CED.2 (Algebra. Creating Equations.)
Essential Questions • How do I find slope using the slope formula? • How do I rewrite an equation in slope-intercept form? • How do I identify the slope and the y-intercept?
Finding Slope M =
–3 – 3 m = 2 – (–1) = = –2 –6 3 Example 1: Find the slope using the following points: A line contains the points (–1, 3) and (2, –3). Find m.
Example 2: Find the slope: (-4, -2) and (2, -2) The slope of a horizontal line is ZERO!
Example 3: Find the slope: (1, 4) and (1, -3) The slopes of vertical lines are UNDEFINED!
Example 4: Find the slope: (4, -2) and (-2, 6)
Example 5: Signs of slope Positive, negative, zero, or undefined:
QUICKLY: Textbook pg. 25, #’s 1-3 all, 14-26 EVEN
Pg. 25, #’s 1-3, 14-26 EVEN • Positive • Negative • Undefined 14. -4/5 16. -3/5 18. Undefined 20. ½ 22. -1/4 24. 1 26. 1
Writing Equations and Identifying “m” and “b” y = mx + b m = slope b = y-intercept **If an equation is not in slope-intercept form, just get “y” by itself. Then, identify the “m” and the “b”.
Example 1 • Write an equation for the given information in slope-intercept form: • M = 2, b = 3 • Y = 2x + 3 • M = -3, b = -4 • Y = -3x – 4 • M = ½, b = -5 • Y = ½ x - 5
Example 2: • Write the equation in slope-intercept form, then identify the m and the b: • -2x + 3y = 9
Example 3 • Write the equation in slope-intercept form, then identify the m and the b: • 4x + y = 3
Example 4: • Write the equation in slope-intercept form, then identify the m and the b: • 5x – 4y = 12
Example 5: • Write the equation in slope-intercept form, then identify the m and the b: • 2x – y = 3
QUICK! Textbook pg. 32, #’s 2-12 EVEN and #14 and #15
Pg. 32, 2-12 EVEN, 14-15 2. 3/2; 1 4. 5; -4 6. -9; 8 8. 3; -1 10. 3; 1/3 12. ¼; 5/8 14. 0; -4 15. undefined; none
Homework: • Workbook pg. 25-27, #’s 1-30 ALL • Workbook pg. 32 #’s 1-12 ALL • SHORT GRAPHING AND INTERCEPT QUIZ THE NEXT TIME YOU COME IN HERE!!!
Pg. 25-27 • Neg • Undefined • Pos • Zero • Pos • Neg • Pos • Zero • Neg • Pos 11. Undefined 12. Neg 13. 1 14. -2 15. 0 16. -1 17. Undefined 18. 2 19. 3/2 20. -1/2
Continued… 21. Undefined 22. 1 23. -5 24. 3 25. -2 26. -6 27. 1 28. -2 29. 0 30. undefined
Pg. 32, #’s 1-12 • 2; 1 • 2/3; 1 • -1/2; 2 • 2; 2 • ½; -1 • 3/2; 1 • 3; 4 • 5; -2 • -2; 8 10. ½; 0 11. -3/4; -1 12. 4; 4