3.4 Find and Use Slopes of Lines
Bell Ringers - Oct 14
(a – b)
1. Evaluate if a = 5, b = 2, c =1, and d = 7
(c – d)
1
(x – 3)
2. Solve = 5
(3 – 4)
2
3. What is the reciprocal of ?
3
4. Julie was thinking of a number. The product of her number and 6 is ­1. What was Julie's number?
Name the angles as corresponding, alternate interior, alternate exterior, or consecutive interior angles
5. ∠4 and ∠7
1 2
3 4
6. ∠11 and ∠14
7. ∠7 and ∠15
5 6
7 8
9 10
13 14
11 12
15 16
3.4 Find and Use Slopes of Lines
3.4 Find and Use Slopes of Lines slope of a nonvertical line: the ratio of vertical change (rise) to horizontal change (run)
positive
negative
zero
undefined
Ex. 1
Find the slope of a line that passes through the points
(­3, 0) and (4, 7)
y2 - y1
7-0
m= x -x =
1
2
4 - (-3)
7
= 7 =1
1
3.4 Find and Use Slopes of Lines
Postulate 17
Slopes of Parallel Lines
In a coordinate plane, two nonvertical lines are parallel if and only
if they have the ______________________________.
Any two vertical lines are ____________.
Postulate 18 Slopes of Perpendicular Lines
In a coordinate plane, two nonvertical lines are perpendicular if and
only if the ____________________________________________.
Horizontal lines are perpendicular to ________________ lines.
Ex 4 Line p passes through (0,-3) and (1, -2). Line q passes through
(5,4) and (-4, -4). Line r passes through (-6, -1) and (3,7).
Find the slope of each line. Tell whether the lines are parallel
or perpendicular or none of these?
Section 3.4: Pages 175 – 178 #1, 2, 4–7, 9, 11, 12, 13–21 odd
2
3.4 Find and Use Slopes of Lines
3.4 Find and Use Slopes of Lines
slope of a nonvertical line: the ratio of vertical change (rise) to
horizontal change (run)
Ex: Find the slope of each line.
m
n
4
2
-6
-4
2
-2
-2
-4
Slope of Lines in the Coordinate Plane
Negative Slope:
Positive Slope
Zero Slope:
Undefined Slope:
4
6
3.4 Find and Use Slopes of Lines
3.4 Find and Use Slopes of Lines
slope of a nonvertical line: the ratio of vertical change (rise) to
horizontal change (run)
Ex: Find the slope of each line.
p
q
4
2
-6
-4
2
-2
-2
-4
Slope of Lines in the Coordinate Plane
Negative Slope:
Positive Slope
Zero Slope:
Undefined Slope:
4
6
3.4 Find and Use Slopes of Lines
3.4 Find and Use Slopes of Lines
slope of a nonvertical line: the ratio of vertical change (rise) to
horizontal change (run)
Ex: Find the slope of each line.
4
g
2
k
-6
-4
2
-2
-2
-4
Slope of Lines in the Coordinate Plane
Negative Slope:
Positive Slope
Zero Slope:
Undefined Slope:
4
6
3.4 Find and Use Slopes of Lines
3.4 Find and Use Slopes of Lines
slope of a nonvertical line: the ratio of vertical change (rise) to
horizontal change (run)
Ex: Find the slope of each line.
j
l
4
2
-6
-4
2
-2
-2
-4
Slope of Lines in the Coordinate Plane
Negative Slope:
Positive Slope
Zero Slope:
Undefined Slope:
4
6