LT: I can graph and write equations of lines Entry Task   LT: I can graph and write equations of lines

2.3 Linear Functions and Slope-Intercept Form Learning Target: I can Graph linear equations I can write equations of lines.

LT: I can graph and write equations of lines Review of Formulas Formula for Slope Point-Slope Form Slope-intercept Form Standard Form *where A>0 and A, B, C are integers LT: I can graph and write equations of lines

LT: I can graph and write equations of lines Slope LT: I can graph and write equations of lines

Examples of linear equations 2x + 4y =8 6y = 3 – x x = 1 -2a + b = 5 Equation is in Ax + By =C form Rewrite with both variables on left side … x + 6y =3 B =0 … x + 0 y =1 Multiply both sides of the equation by -1 … 2a – b = -5 Multiply both sides of the equation by 3 … 4x –y =-21 LT: I can graph and write equations of lines

Examples of Nonlinear Equations The following equations are NOT in the standard form of Ax + By =C: The exponent is 2 There is a radical in the equation Variables are multiplied Variables are divided 4x2 + y = 5 xy + x = 5 s/r + r = 3 LT: I can graph and write equations of lines

LT: I can graph and write equations of lines Find the slope of a line through points (3, 4) and (-1, 6). LT: I can graph and write equations of lines

Write an equation for the line that passes through (-2, 5) and (1, 7): Find the slope: Use point-slope form: LT: I can graph and write equations of lines

LT: I can graph and write equations of lines Change into slope-intercept form and identify the slope and y-intercept. LT: I can graph and write equations of lines

LT: I can graph and write equations of lines Change into standard form. LT: I can graph and write equations of lines

x-intercepts and y-intercepts The intercept is the point(s) where the graph crosses the axis. To find an intercept, set the other variable equal to zero. LT: I can graph and write equations of lines

LT: I can graph and write equations of lines Horizontal Lines Slope is zero. Equation form is y = #. Write an equation of a line and graph it with zero slope and y-intercept of -2. y = -2 Write an equation of a line and graph it that passes through (2, 4) and (-3, 4). y = 4 LT: I can graph and write equations of lines

LT: I can graph and write equations of lines Vertical Lines Slope is undefined. Equation form is x = #. Write an equation of a line and graph it with undefined slope and passes through (1, 0). x = 1 Write an equation of a line that passes through (3, 5) and (3, -2). x = 3 LT: I can graph and write equations of lines

LT: I can graph and write equations of lines Graphing Lines *You need at least 2 points to graph a line. Using x and y intercepts: (plug 0 in for x and then y) Find the x and y intercepts Plot the points Draw your line LT: I can graph and write equations of lines

Graph using x and y intercepts 2x – 3y = -12 x-intercept 2x = -12 x = -6 (-6, 0) y-intercept -3y = -12 y = 4 (0, 4) LT: I can graph and write equations of lines

Graph using x and y intercepts 6x + 9y = 18 x-intercept 6x = 18 x = 3 (3, 0) y-intercept 9y = 18 y = 2 (0, 2) LT: I can graph and write equations of lines

LT: I can graph and write equations of lines Graphing Lines Using slope-intercept form y = mx + b: Change the equation to y = mx + b. Plot the y-intercept. Use the numerator of the slope to count the corresponding number of spaces up/down. Use the denominator of the slope to count the corresponding number of spaces left/right. Draw your line. LT: I can graph and write equations of lines

Graph using slope-intercept form y = -4x + 1: y-intercept (0, 1) Slope m = -4 = -4 1 LT: I can graph and write equations of lines

Graph using slope-intercept form 3x - 4y = 8 y = 3x - 2 4 y-intercept (0, -2) Slope m = 3 4 LT: I can graph and write equations of lines

LT: I can graph and write equations of lines Homework Homework: p. 78 #7, 11, 19, 23, 25, 27, 29, 33, 37, 39, 43, 49, 53, 58 Challenge - # 62 LT: I can graph and write equations of lines