1. Warm-up 3-7: Survey

2. Lesson 3-7: Parallel & Perpendicular Lines
Objectives
Students will:
Use equations to determine if two lines are parallel or perpendicular
Write an equation of a line that is parallel or perpendicular to a given line

3. Graph the following lines
y = 2x + 1
2x – y = 3

4. Look at the slopes from the graphs: Parallel lines → same slope
Perpendicular line → “opposite reciprocal” slope
Writing Equations
Get the slope you want
Plug it and a given point into y = mx + b, solve for b
Remember:
slope = m &

5. Example 1: y = 5x + 2 ; y = -5x + 2 Parallel, perpendicular, or neither?
Example 2: Write an equation for a line parallel to y = 5x + 4 through (1, 3)
Example 3: Write an equation for a line perpendicular to 3x + 4y = 5 through (3, -2)