Slope-Intercept Form: Slope-Intercept Form Algebra Review: Review Slope = vertical change = y 1 – y 2 = rise horizontal change = x 1 – x 2 run Ex. (-2, 1) & (6,7) 7 – 1 6 3 6 – (-2) = 8 = 4 Horizontal line = slope 0 Vertical line = slope undefined Line from upper left to lower right = negative slope Line from lower left to upper right = positive slope Slope-Intercept Form: Slope-Intercept Form Linear function: a function that graphs a straight line Modeled by a linear equation Y-intercept: where the line crosses the y-axis Found when x=0 Slope-intercept form: y=mx+ b m = slope b = y-intercept Ex. Write an equation of the line with a slope of 3/8 and y-intercept of 6. y = mx + b … so… y = 3/8 x + 6 Slope-Intercept Form: Slope-Intercept Form If you have 2 points on a line you can find the slope – intercept form. Ex. (0, 2) and (4, -1) slope (m) = 2 – (-1) = 3 y-intercept (b) is the y value when x is 0. 0 – 4 -4 (0, 2) x = 0 when y = 2 slope-intercept form: y = mx + b y = -3/4 x + 2 Slope-Intercept Form: Slope-Intercept Form If you have the slope intercept equation you can graph the line. y = 3x – 1 slope = 3 or 3/1 (rise = 3, run = 1) y-intercept = -1 …so…(0 , -1) is one point on the line Begin with the known point. (0, -1) Then, count up another 3 and over 1 again. (2, 5) Next, count up 3 (the rise) and over 1 (the run). (1, 2) Watch the videos linked below: Watch the videos linked below Click on the links below to see further discussion: http://www.khanacademy.org/math/algebra/linear-equations-and-inequalitie/equation-of-a-line/v/linear-equations-in-slope-intercept- form Please copy the examples given in the videos into your notes Practice: Practice Click on the link below to practice identifying parts of a function. http://www.khanacademy.org/math/algebra/linear-equations-and-inequalitie/equation-of-a-line/e/ slope_intercept_form Further Reference: Further Reference For more information or examples on this topic, please see: Textbook p. 317-323 http://www.purplemath.com/modules/ strtlneq.htm http://www.mathwarehouse.com/algebra/linear_equation/slope-intercept- form.php http://www.youtube.com/watch?v=u3spOO- m_Gg Please write down any specific questions you have so we can discuss them in class!!