3. Example 2.
Example 1. Determine the
slope of the lines y = 2x + 4 and y =
2x – 2. Sketch the graph.
Parallel Lines
Two non-vertical lines are parallel if and only if they have the same slope.
5. Example 4.
Determine the slope of the lines y =
3
4
x –
2 and y = -
4
3
x + 1.
Perpendicular Lines
Two non-vertical lines are perpendicular if and only if the slope of
one line is the negative reciprocal of the other line.