3.6 Lines in a coordinate plane

Algebra 1 Review Slope of a Line: Ratio of its vertical change to the corresponding horizontal change (“rise over run”) x y

Algebra 1 Review Slope of a Line: Ratio of its vertical change to the corresponding horizontal change (“rise over run”) x y

Algebra 1 Review Find the slope of the line below.

Algebra 1 Review Graph the line that contains the point (2,1) and the slope of… 1) 2) 3)

Forms of a Line Slope-Intercept Form: m = slope b = y-intercept Standard Form: A,B are integers ≠ 0 and A > 0 Point-Slope Form: m = slope (x1,y1) = point on line

Graphing Lines in Slope-Intercept Form Graph the line .

Graphing Lines in Standard Form Graph the line 2x + 3y = 6. Method 1: Transform to Slope-Intercept Form

Graphing Lines in Standard Form Graph the line 2x + 3y = 6. Method 2: Find intercepts

Using Point-Slope Form Write an equation in point-slope form of the line through point P(-1,4) with slope 3.

Using Point-Slope Form Write an equation in point-slope form of the line through the points A(-2,3) and B(1,-1).

Horizontal and Vertical Lines Let’s take a look at the vertical line and horizontal line through the point (-3,1). Horizontal Lines Slope = 0 Equation: Vertical Lines Slope Undefined Equation:

Horizontal and Vertical Lines Write equations for the horizontal line and the vertical line that contain the point (2,-5).

Slope and Parallel Lines Slopes of Parallel Lines: 1) If two nonvertical lines are parallel, their slopes are equal. 2) If the slopes of two distinct nonvertical lines are equal, the lines are parallel. 3) Any two vertical lines are parallel.

Slope and Perpendicular Lines Slopes of Perpendicular Lines: 1) If two nonvertical lines are perpendicular, the product of their slopes is -1. 2) If the slopes of two lines have a product of -1, the lines are perpendicular. 3) Any horizontal line and vertical line are perpendicular.

Thinking Page Directions: Write in paragraph form and in complete sentences. Answer the following questions. What was the teaching point of the lesson? How is it meaningful to you and relevant beyond the lesson?