1. Parallel and Perpendicular Lines
Objective:
Find the equation for a line parallel or perpendicular to a given equation and point.
Graph parallel and perpendicular lines.

2. Practice Write the reciprocal of each. -2 ¾ ½ 3 -¼
Reciprocal means you take the flip:
¾  4/3
5  1/5

3. Parallel Lines
If two linear equations have the ______ slope, then they are parallel.
Graph the lines. x y
y =
y =

4. Perpendicular Lines
If two linear equations have __________, _____________ slopes, then they are perpendicular.
Graph the lines: x y
y =
y =

5. You Try m= m= Give the slope of a line: Parallel to y =
Perpendicular to y = m= m=

6. Writing an Equation for Parallel
Write an equation for a line parallel to y = -3x + 2 and passing through the point (-3,2).
Parallel lines have the ____ slope; therefore,
y= mx + b
m =

7. Write an Equation for Perpendicular
y = mx + b
Write an equation for a line perpendicular to
y = 4x + 2 and passing through the point (-8,4).
Perpendicular lines have ________________ slopes; therefore, m = ______.

8. You Try Find the equation for the line:
Parallel to y = 3x – 2 and passing through (6,-1)
Perpendicular to y = 4x + 5 and passing through (-8,2)
Parallel to y = ½ x and containing (0,-5)
Perpendicular to y = 2/3 x –8 and containing (-6,3)