1. College Algebra K/DC Friday, 23 January 2015 OBJECTIVE TSW write equations for lines in standard form and slope-intercept form. ASSIGNMENT DUE I will take a few HW questions before turning it in. –Sec. 2.4: pp. 227-231 (65-68 all, 73-77 all, 88-92 all)  wire basket

2. R2-2 Equations of Lines; Curve Fitting 2.5 Standard Form ▪ Slope-Intercept Form ▪ Point-Slope Form

3. Equations of Lines Standard Form Ax + By = C A, B, and C are integers A is positive Slope-intercept Form y = mx + b m is the slope, b is the y-intercept Point-Slope Form y – y 1 = m(x – x 1 ) m is the slope, (x 1, y 1 ) is any point on the line

4. 2-4 Find an equation of the line through (3, –5) having slope –2. Write the answer in slope-intercept form. Using the Point-Slope Form (Given a Point and the Slope) Point-slope form: y – y 1 = m(x – x 1 ) x 1 = 3, y 1 = –5, m = –2

5. 2-5 Find an equation of the line through (–4, 3) and (5, –1). Write the answer in slope-intercept form. Using the Point-Slope Form (Given a Point and the Slope) First, find the slope: Use either point for (x 1, y 1 ) Point-slope form

6. 2-6 Find the slope and y-intercept of the line with equation 3x – 4y = 12. Find the Slope and y -intercept From an Equation of a Line Write the equation in slope-intercept form: The slope is and the y-intercept is –3. Also, m = −A / B, b = C / B.

7. 2-7 Find an equation of the line through (–2, 4) and (2, 2). Then graph the line using the slope- intercept form. Using the Slope-Intercept Form (Given Two Points) First, find the slope: The equation is Substitute for m and the coordinates of one of the points (say, (2, 2)) for x and y into the slope-intercept form y = mx + b, then solve for b:

8. 2-8 Using the Slope-Intercept Form (Given Two Points)

9. 2-9 Use the graph to (a) find the slope, y-intercept, and x-intercept, and (b) write the equation of the function. Finding an Equation From a Graph The line rises 5 units each time the x-value increases by 2 units. The slope is.

10. 2-10 Finding an Equation From a Graph The graph intersects the y-axis at (0, 5) and the x-axis at (–2, 0). The y-intercept is (0, 5). The x-intercept is (–2, 0).

11. 2-11 Finding an Equation From a Graph Slope, y-intercept 5

12. Converting to Standard Form Convert the following to standard form. A, B, and C are integers, A is positive.

13. Converting to Standard Form Convert the following to standard form.

14. Converting to Standard Form Convert the following to standard form. The LCD is 10, so multiply both sides by 10.

15. 1-4) matching equations with graphs (get from the book on your own) Write an equation for the line described. Give answers in standard form (Ax + By = C). 5)through (1, 3), m = –26)through (2, 4), m = –1 7)through (–5, 4), 8)through (–4, 3), m = –3 / 2 m = 3 / 4 Write an equation for the line described. Give answers in slope-intercept form (y = mx + b). 13)through (–1, 3) & (3, 4)14)through (8, –1) & (4, 3) 15)x-int. 3, y-int. –216)x-int. –2, y-int. 4 21)m = 5, b = 1522)m = –2, b = 12 23)m = –2 / 3, b = –4 / 5 24)m = –5 / 8, b = –1 / 3 Give the slope and y-intercept and graph. 31)y = 3x – 132)y = –2x + 733)4x – y = 7 34)2x + 3y = 1635)4y = –3x36)2y – x = 0 37)x + 2y = –438)x + 3y = –939)y – 3 / 2 x – 1 = 0 Sec. 2.5: p. 242 (1-8 all, 13-16 all, 21-24 all, 31-39 all) Due on Monday, 26 January 2015.

16. College Algebra K/DC Monday, 26 January 2015 OBJECTIVE TSW write equations for lines in standard form and slope-intercept form. ASSIGNMENT DUE –Sec. 2.5: pp 242-243 (1-8 all, 13-16 all, 21-24 all, 31- 39 all)  wire basket QUIZ: Sec. 2.4 & 2.5 is tomorrow, Tuesday. Get out your complimentary straightedge. IN-CLASS ASSIGNMENT –ACTIVITY: Parallel and Perpendicular Lines –When you finish, work on today’s assignment (due tomorrow).

17. R-17 Equations of Lines; Curve Fitting 2.5 Vertical and Horizontal Lines ▪ Parallel and Perpendicular Lines

18. Vertical and Horizontal Lines Vertical lines –Have undefined slopes –Are of the form x = a (a is a constant) –Have No y-intercept (except when the line is x = 0) –Are not functions Horizontal lines –Have slopes equal to 0 –Are of the form y = a (or f (x) = a) (a is a constant) –Have no x-intercept (except when the line is y = 0) –Are constant functions. In-Class Activity: Parallel and Perpendicular Lines You may work with someone. Due before you leave today (black tray).

19. Assignment – Sec. 2.5: pp. 242-244 (9-12 all, 17-20 all, 25, 26, 28, 47-56 all) Due on Tuesday, 27 January 2015. Write an equation for the line described. Give answers in standard form (Ax + By = C). 9)through (–8, 4), m undefined 10)through (5, 1), m undefined Write an equation for the line described. Give answers in slope-intercept form (y = mx + b). 11)through (5, –8) m = 012)through (–3, 12) m = 0 17)vertical through (–6, 4)18)vertical through (2, 7) 19)horizontal through (–7, 4)20)horizontal through (–8, –2) 25)slope 0, y-int 3 / 2 26)slope 0, y-int –5 / 4 28)matching – get from book Write an equation (a) in standard form and (b) in slope-intercept form for the line described. 47)through (–1, 4), parallel to x + 3y = 5 48)through (3, –2), parallel to 2x – y = 5 49)through (1, 6), perpendicular to 3x + 5y = 1 50)through (–2, 0), perpendicular to 8x – 3y = 7

20. Assignment – Sec. 2.5: pp. 242-244 (9-12 all, 17-20 all, 25, 26, 28, 47-56 all) Due on Tuesday, 27 January 2015. Write an equation (a) in standard form and (b) in slope-intercept form for the line described. 51)through (4, 1), parallel to y = –5 52)through (–2, –2), parallel to y = 3 53)through (–5, 6), perpendicular to x = –2 54)through (4, –4), perpendicular to x = 4 55)Get from the book. Be sure you can do this. 56)Get from the book. Be sure you can do this.