1. Objective: To write equations of parallel and perpendicular lines.
Ch 5.6
Objective:
To write equations of parallel and perpendicular lines.

2. Definitions
Parallel Lines have the SAME slope Perpendicular Lines Have opposite and reciprocal slopes { {
Sign changes
“flip” the fraction

3. Determine if the following pairs of equations are Parallel, perpendicular, or neither:1 2 1 2
1) y = x + 2 and y = x - 1
Parallel 2 3
- 3 2
2) y = x – 3 and y = x + 2
Perpendicular 1 4
3) y = 4x + 1 and y = x - 3
Perpendicular 2 3 2 3
4) y = x – 1 and y = x + 2
Parallel 2 5 3 5
5) y = x – 1 and y = x + 2
Neither

4. Graph the following on the coordinate plane.y x
Parallel lines have the same slope.

5. Find the equation of a line in standard form that
is parallel to 3x - 5y = 10 and contains (-2,6).
(-2,6)
3x - 5y = 10
-3x x
-5y = -3x + 10 or

6. Perpendicular lines have slopes that are
Graph the following on the coordinate plane. y x
Lines appear
perpendicular
Perpendicular lines have slopes that are
opposite reciprocals

7. Find the following:
Opposite
Reciprocal
Number
Opposite
Reciprocal 3
0.2 -8

8. Find the equation of a line in standard form that
is perpendicular to 4y - x = 6 and contains (2,5).
4y - x = 6
(2,5)
+x +x
4y = x + 6

9. Determine whether the slopes are perpendicular.1)
Yes, perpendicular. 2)
No, not perpendicular. 3)
Yes, perpendicular.

10. Find the equation of a line in standard form that is
perpendicular to 3x + 5y = 7 and contains (-4,-8).
(-4,-8)
3x + 5y = 7
-3x x
5y = -3x + 7 or