Slopes…… • Parallel Lines: The slopes are EQUAL for parallel lines. • Perpendicular Lines: The slopes are opposite reciprocals for perpendicular lines.
Example……If • PARALLEL: • PERPENDICULAR:
You Try. . . . • Parallel: • If find the parallel and perpendicular slopes. • Perpendicular:
You Try…… • If find the parallel and perpendicular slopes.
Answer……Remember • Parallel: • Perpendicular:
Example…… • A. What is the slope of • A. ? • B. What is the parallel • B. • C. What is the • C. slope? perpendicular slope?
Example…… • Graph the line parallel to through (8, 2).
Answer…. . Parallel to
Graph …….
Example……. • Graph the line perpendicular to through (3, 2)
Answer…Perpendicular to
Graph……
Are the following lines parallel, perpendicular, or neither? . . • Answer: • They have the same slope so they are parallel.
Parallel, Perpendicular, or Neither? • The slopes are not the same so they are NOT parallel. • The slopes are not opposite reciprocals so they are NOT perpendicular. • They are neither.
Parallel, Perpendicular, or Neither? . . . • You must first change both into slopeintercept form. • Now, you can compare their slopes.
• They are not the same so they are NOT parallel. • They are not opposite reciprocals so they are NOT perpendicular. • They are neither.
Parallel, Perpendicular, or Neither? . . . • Change to slope- intercept form first. • Compare their slopes.
• The slopes are opposite reciprocals so they are perpendicular.