1. Warm-Up On the same coordinate plane… ▫Graph the equation y=2x +3 ▫Graph the equation y=2x ▫Graph the equation y= - ½x + 1 What do you notice about the three lines?

2. Homework Review P. 326 #8-26E 8. (9, 0) and (0,9) 10. (-7/3, 0) and (0, 7/3) 12. (3, 0) and (0, -21) 14 – 16. Graph 18. (-3, 0) and (0, -3) 20. (-4, 0) and (0, 8) 22. (3, 0) and (0, -9) 24. Vertical 26. Vertical

3. Section 5.6 Parallel and Perpendicular Lines

4. Parallel Lines Parallel Lines are lines in the same plane that never intersect Two non vertical lines that are parallel have the same slope Any two vertical lines are parallel

5. Example A line passes through (12, 5) and is parallel to the graph of y=2/3x -1. What equation represents the line in slope intercept form?

6. Perpendicular Lines Two lines are perpendicular if they intersect to form right angles Two lines are perpendicular if their slopes are opposite reciprocals Any horizontal and vertical lines are perpendicular

7. Example Write an equation in slope intercept form for a line that passes through (2, 4) and is perpendicular to the graph of y=1/3x – 1?

8. Example Determine if the two lines are parallel, perpendicular, or neither.

9. Example Determine if the two lines are parallel, perpendicular, or neither.