writing equations of parallel and perpendicular lines
TRANSCRIPT
Writing equations of parallel and
perpendicular lines
X
Y
Y = ½X + 6
Y = -²/₁X + 0
Y = ½X - 4
Parallel lines ALWAYS have the same slope
Perpendicular lines have OPPOSITE RECIPROCAL slopes
Write the equation of the line that goes through point (-3, -5) and is parallel to the line Y = 3X - 1
Y = mX + bx y m
-5 = (3)(-3) + b-5 = -9 + b
+9+94 = b
Y = 3X + 4
Write the equation of the line that goes through point (4, -5) and is perpendicular to the line Y = 2X + 3
Y = mX + bx y m
-5 = (-½)(4) + b-5 = -2 + b
+2+2-3 = b
Y = -½X - 3
Determine which lines if any are parallel or perpendicular a) 2X + 6Y = -3 b) Y + 8 = 3X c) -15Y + 45X = 60
-2X-2X
6Y = -3 – 2X6 6
-3 6
- 2X 6
-1 1 2 3
- X
- 8- 8
Y = 3X - 8-45X
-45X
-15Y = 60 – 45X-15 -15
60-15
45X-15
-
Y = -⅓X - ½
-4 3 1 1
+ X
Y = 3X - 4
Parallel lines are… b and c
Perpendicular lines are… a and b a and c