This document discusses parallel and perpendicular lines. It defines parallel lines as having the same slope and perpendicular lines as having negative reciprocal slopes. It provides examples of finding the negative reciprocal of slopes, identifying parallel and perpendicular lines based on their slopes, writing equations of lines parallel and perpendicular to given lines through given points, and word problems involving parallel and perpendicular lines.

1. Bell Work Tell if data is linear. If so, write the equation. 1) 2) 3) x y -4 9 2 -3 5 -9 9 -17 x y -10 -5 -2 17 5 42 11 49 x y 3 1 6 4 9 13 15 49

2. Algebra 1 Parallel & Perpendicular Lines School Day: 17 Objective: 2.02

3. Notes Parallel lines are two lines that never intersect. They have the same slope. Perpendicular lines are two lines that intersect to form right angles. They have negative reciprocal slopes. (example: m = 2/3 and m = -3/2)

4. Examples What is the negative reciprocal? 1) 2 2) -1/3 3) 4/5 4) -3/2

5. Examples y = -2/3x + 7 b) y = -3/2x + 4 y = 2/3x – 4 d) y = -2/3x – 2 5) Which lines are parallel? 6) Which lines are perpendicular?

6. Examples Write an equation in slope-intercept form that is parallel to the given line through the given point. 7) y = ½ x + 1 (4,2) 8) 2x + y = 5 (4,-6)

7. Examples Write an equation in slope-intercept form that is perpendicular to the given line through the given point. 9) y = 1/6x – 1 (2,4) 10) 5x + 4y = 8 (10,5)

8. 11) In Elmsville, Main St. has the equation 2y = 7x + 6. If First St. is parallel and three streets up, what would be its equation? 12) In Coal City, Oak St. has the equation 3x + y = 4. If Elm St. is perpendicular and two streets down, what would be its equation?