Warm-up 3-7: Survey
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
Graph the following lines y = 2x + 1 2x – y = 3
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 &
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)