1. 3-6 Slopes of Parallel & Perpendicular Lines M11.B.2 2.3.11.A
Objectives:
To relate slope and parallel/ perpendicular lines

2. Slopes of Parallel Lines
If two nonvertical lines are parallel, their slopes are equal
Any two vertical lines or horizontal lines are parallel.

3. Slopes of Perpendicular Lines
If two nonverticl lines are perpendicular, their slopes are OPPOSITE, RECIPROCALS!!
Any horizontal line and vertical line are perpendicular.

4. Example: Check for Parallel or Perpendicular Lines
Line 1 contains P(0,3) and Q(-2,5). Line 2 contains R(0,-7) and S(3,-10). Are lines 1 and 2 parallel, perpendicular, or neither?

5. Check for Parallel/Perpendicular Lines
Line x contains A(-4, 2) and B(0, -4). Line y contains C(4, 3) and D(-5, -3). Are lines x and y parallel, perpendicular, or neither? Explain

6. Determine whether the lines are parallel, perpendicular, or neither
Determine whether the lines are parallel, perpendicular, or neither. Explain
y = 5x + 4
y = -5x - 4

7. Are the lines parallel, perpendicular, or neither? Explain.
1. y = -2 x + 5 and 2x + y = 9
2. 2x + 3y = 6 and 6x – 4y = 24

8. Example: Write equations of Parallel Lines
Write an equation in Point-Slope Form for the line parallel to y = -4x + 3 that contains (1, -2)

9. Write equations of parallel lines
Write an equation in Point-Slope Form for the line parallel to y = -x + 3 that contains (-2, 5)

10. Equations for Perpendicular Lines
Write an equation in Point-Slope Form for a line perpendicular to y = -3x - 5 that contains (-3, 7).